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Napoleon, 238, 261

Naphtha and gas tar, 22

Napkin rings, 430, 470

Natal, passage to, 287, 427

Niitural: forces, 623; selection, 311, 499

Naturalisation, 875, 620

Nature, sketching from, 166, 4"4, 427

Naval architecture, 191, 259, 28-3, 382

Needle: magnetic, 263, 286, am, 417 •
wires, tempering, 598

Negatives, paper. 23

Neptune, the planet, 94, 117

Nets, 405; tints, flshennon's, SOS, 380

Netting machine, wire, 382

New: comet, 058; dye-wood, 502; vcloce

saddle spring, 383, 429; worm lor vico-

box. 46, 92

New Zealand, 118

Newark's cement, 142

Nickel, 237, 260

Nicol prism, the, 118

Nicotine, 67, 93, 116

Nitrate of Bilvor, 550. 673. 574, 597. 598,

IB!0; nitrate of silver stains, 215, 2U0

Nitric acid, 45; nitrous acid, 598

Nozzles, size of, 238. 309

Nuggets. Australian. 623

Numhoring books, 18; numbers, powers

of, 262, 286

Numerals, Roman, 311
Numismatical. 623
Nut-shaping In lathe, 23, 45; nuts •

bamboo, 262; Kola, 167, 189
Nux vomica, tests for, 311, 404

OAK: beam 69, 93 j stains, 262

Oats, barley from, 527, 549

Object: glasses, 21, 22, 44, 67, 70, 91, 139,

166,386, 358; object, height of, 478, 524;

objects, microscopical, 430, 454,455, 476.

478, 479, 525

Oboe, 618

Observatory, 335

Occultation of Saturn, 574, 598

Oil: brick, 382, 406, 429; cod-liver. 383

454, 477, 800, 671, 594: colza, 117 164

454, 500, 623, 571, 675; Gouia, 650 \

paint from silk, removing, 45. »2;

paraffin. 648; testing, 287, 310, 406, 438-
varnish, 358, 381 ; oils, 5.50
Oil paper, 190, 237
Ointment, 214
Okc, Turkish, 118, 141
Old coins, 94. 117. 118, 142, 105, 187, 188.

1!«), 239, 259, 261

Oleic acid, 142

Oliver Cromwell shilliug. 308, 8«I

Optical, 238, 450, 500

Orchis, 381

Ores: auriferous. 45; iron, 46: lead 430

Organ, the. 22, 69. 167, 21.5, 263, 287, 310,

334, 428, 550. .573, 596 ; organ: accordion

stand. 262, 4.52, 5461 barrels. 287. 42s,

47-3, .523; movement to harmonium,

287: pipes. 311, 334, 622; stops, 287;

orgaus: reed, 358; twu-iuanua), loo

188, 213

Ornamental wood and metal cutting

machine, 22

Ornaments, steel, 19

Oscillating cylinder, 622

Ovals, 46, 68," 502, 526. 648

Overland route, 22. 91

Oxford. Agricultural Exhibition, 69

Oxygen, 238, 885; oxygen holder, 602
Oxynydrogen microscope, 574
Oyster shells, pearl, 599

PADDLE steamer, model, 599; pad-
dle, swimming. 623

Paint 95; paint: for aquarium, 383, 694;

for boats. 262: on bicycles, 21, 66;

granitic, 26, 66; hard white. 452; retnelt-

iug, 202; removing. 202. 286

Tainting: ancient, 456; bath. 623; boiler,

262: bronzing and painting iron. .5.30;

carriages, 22; cistern, 627. 572; coaches,

5.30, 619; decorative, 191, 237; glass,

167, 835. 380; landscape, 166; stones In

jewellery. 215, 427; tarred wood. 160,

189, 236; theatrical scenes, 4-5, 08 92;

windows, 262, 286

Palisading, iron, 160, 189, 23G

Palo de Velas. 46, 92

Pancreatic tubes. 189, 236

Pancreatic emulsion, 574; pancreatine,
674

Pans: harmonium, 213, 627; loam, 262
499

Paper: collarsand cuffs, 190, 237; mourn-
ing. 5112; negativos, 23; oiled, 190, 237;

staining, 9.3: stencilling, 117. 187: trac-

ing. 285, 602, 62.5, 547; waterproofing

118. Ill, 167; varnish. 94

raper-banging*, 142, 143, 189, 236, 336,380

Papers: fly, 336. .'ISO; tobacco, 93

Paraliolical reflector, 623

Paradox: apparent, 43, 91; pneumatic,

Paraffin: oil, 649; scale, 262, 286; trans-

parent, 190; paraffin lamp, cement for

18, 20'

Parasites on canaries. 280, 333

Parehmout, artificial, 94

Paris, 382; Paris, plaster of, 599, 621

Parsons's white brass, 311

Part of sphere contents of, 118

Passage to Natal, 287, 427

Paste: for clothing iron roller.-:, 21;

razor, 19; for stropping tools. 9.5

Pasteboard, 167. 236, 401; pasteboard,

usphnlte. 238, 261

Pa Milks, 238. 261

Paths, garden. 479, 501, 82.5

Patent: coll, Varleva. 20: drl»n, 46

116; pioon, Mather's. 478, 825

[ocr errors]

Pattern varnish, 18, CO, 91; patterns

cylinder. 215, 260; girder, 166, 213,

259; making. 118; measuring, 43

Paving, asphalte. 479, 601, 625

Pearl oyster shells, 699

Pebbles, Scotch, 46, 68

Pedal pipes, 69

Pedestrian tours, 623

Pedometers, 18, 574, 598, 020

Pen, drawing, 382, 428; pons, :,»■>

Pencil for lathe, 94; pencils, load, 45 92

Pendulum. 43, 4-5, 527,649, 540, 872.623;

pendulum Bprings for watch, 697, Olo'

622

Poppcrmoth, 117, 139. 141

Perch Ashing, 626, 649, 571

Perforating for embroidery, 40 110

Periodicals, Belgian ami French, 18

Perry's microscope, 335, 380

Pestle and Mortar, 66

Phenomena: astronomical, 526 690-

strange, 479. 625

Phosphate of lime, 338, 880

Phosphorus. 20

Photographic, 20. 23. 46, 92, 96, 187, 214

215, 311, 333, 369, 381, 382, 427, 428, 482

478, 4711, 521, 638, 526. .327. 647. 519. 57l'

573. 675,50.5,698, 618, 619,620; photo-

graphic: camera, 191, 259, 309; views,

W8; photographs or Aust ralian scenery.

Photozincography, 21

Physiognomy. 19*

Pianoforte, 1 iai; pianofortes: defective, in-

felt, for, 2:t8; keys and teeth of, 66-

pins, tightening of, 382, 476, 550, 596 \

Kitchener's grand, 94

Pickles, 2G2

Picric acid. 650, 873, 596

Picture mount, 238

Piece, brake, 574, C20

Pig iron, 70, 139

Piko fishing, 882, 400
Pills, 20, 66
Pine wood, 21
Pinions of watches. 478
Pius: brooch, 94,117, 140; piauo, 382, 476

550, 596
Pipes: flexible, 287.427; organ, 311, 084
022; pedal. 69; staain, 43, 66, 190 2011:
sweating water, 20; syphon, 190. 2,3a
Piston and pressure, 899; pistons: Mather
and Piatt's, 478, 525; Bamsbottoms.
358, 403

Pitch, 20; pitch pine wood, 21: pitch of

propeller, 215, 200; pitching cogwheels,

94

Pivots: turning. 238, 261; watch. 186, 239

Plane mirror, mounting, 527, 547; plant's

diagonal, 191

Planet Neptuno, 94. 117; planets, situa-
tion of, 190
Planing machine, .182, 622
Plans: aviary, 5.30; canoe, 335; printing

names on. 118. 141, 187

naming, 430. 470

Plants: starch, 215; zinc, 20, 06

Pianuo, Wedgwood. 70. 98

Plaster: court, 454, 5011, 623; felt and

amadou. 21; from glass, removing

526; hardening, 190. of Paris. 599. 621

Plate-glass, gilding. 166, 213: plates: ba-

lance, metal 502; battery, 20: boiler-

359; brass. 94, 527, 69(1; burnishing 215'

427; copper, 167. 236: dividing. 21 44'

238, 261; division, 527, 549, 672 018-

screw, 4.50, 478; steel, 308, 381, 527-'
stencil 20
Platelayers' instructor, 21
Plating, electro, 118
Piatt and Mather's piston, 478, 620
Plough, bookbinders', 190, 2.39
Plumbago: dissolving,238; bottle battery

479, 502
Plush, dye. for, 94
Pneumatic paradox, 119
Points: of drills, 023; legal 027 049-
melting, 527 *

Poisoning: oantharidea, 191, 214, 237 259

Polariscope. 430

Polarised light, 311, 3-37, 380, 428

Poles, magnetic, 40, 68, 262

Polishing: copper, 311; faceted gold

chains. 215; fretwork, 4<i; granite 40

104: horn and shells, 46; plaster of

Paris. 599, C21; Scotch pebbles. 46, 68 •

speculum, 430; steel, 211, 237. 2601

stones, 09: vulcanised india-rubber
•5 i0; vulcanite, 673, 596; walking sticks'
690; watch pivots. 106. 258
Pond for gold fish, 574, 020
Porous: castings, 260; cells, 118, 285,

Portable: carpenters' benoh, 45; engine
94, 140; mill. 050, 69S «"«u«.

Position of magnetic pole, 262

Potass, ferrycyanido of, 501

Pottery: bricks and, 287, 358, 403- glaze
for. 190, 236 B

Powder: bleaching, 238, 427, 402; blue

44; soap. 480; teeth. 119. 141, 164

Power, boiler, 211; double motive, 23s

310; engine, 574, 598; horse, 310 334'

330. 502, 526. 627, 547. 64a 550. 595. 096 •'

lifting, 21, 44; of metal, twisting, 189

259, 285; motive, 623; numbers 262

286: of spiral springs, 22; steam, 45

92; of telescopes, 189; for velocipede

479; water. 43. 40, 60. 68. 92, 139 S7l'

622; of water wheel, 573, 610

Preceptors. College of. 69

Precipitating: cochineal, 3-59, 571: gold

238.402 .«•»«.

Preparing: canvas, 23,8, 355; rhoa fibre,

Preserves, 202

Preserving: eggs. 189; floivers, .111, 335,
507; kla boots, 47-i; meat. 94, no

Presses: binders' cutting, 21, 41; steam
punching, 527

Pressing ladles into shape. 210

Priwsure: boiler, 310, 350, 338. 379; on
columns, 21, 67; gauge, gas. i,W: piston
•<99; want of. 430: water, 071. .508, 620

Preventing inhalation of iron and dust.

Prices: boat, 93; carpenters' work, Is-

sawing timber. 214

Pricking barrels of organs, 2S7, 475 623

rrio-dleu. 40

I'rinic movers, 311

Primroses. 210, 260, 30!1, :13a

Printers' furniture, 287

Printing, 4-34: printing: anastatic, 335-

books on. 8.38. 381; copper-plate 94- to

gold or bronze. ,3.50, 072; nanies ' on

plans, 118. 141, 187

Prints: on cardboard, 599; cleaning 502

020; for docoration, 166,404; on glass'

400; Impressions from, 502 017-

wrinkles in. 699

Prisms: bisulphide of carbou, 202 475-

iron. 166,427; Nicol, 18

Problems: 19, 21, 22. 44, 43, 67 69 11

02. 118, 118, 141, 142, 160. 215 W

286, 33.3, 357, 404. 431, 4-54. 476, 477 478

500. 501. 624, 650, 574, 5D5, 097 51S 619'

620, 622

Process. Swan's, 46, 92

Proctor's telescope stand, 698

Projectiles, range of, 330

Projection: 70. 93. 140. 142, 188; projec-

lions, map. 166. 213. 466

Propagation of geraniums, 509

Propellers, screw. 218, 260. 57.5

Propelling vessels by windmill 550 57-1

596, 619

Proportions or space, 143. 165, Isl

Protecting wood and iron, 70'

Protractor, 23, 08

Proving steam boilers. 214

Pthah. greater, 167, 451

Publishing music, 94, 140

Pulleys: loose, 214, 239; Mcndoza, 215;

size, of 46 —i •« ■

Pulp from leather. 22

Pumps, 44. 66, 117, 141; pumps- air

strung, 335, 380; Appold's. 24, 140: force,

15, 287. 406. 594; model engine 113-

water, 308, 381 ''

Punching press, steam. 027

Pure charcoal, 026, 549
Purifying: nitric acid, 4-5; water. 099
Putting tho Bhot, 47,8
Putiv, 18

BAD BHEII, 238

Bigs, wot, 142

Hiding, hand, 142. 238. 360

Bails; circular, 22; weight of, 527,596,

Bailway guard's watch, 311, 307, 380-

railways, Brazilian, 287, 810

Raising water, 46, 92, 148. 61)2

Bamsbottom's pistons. 80s, 400

Range of projectiles, 335

Razors: etching, 66; paste for, 19

Readings from tho globes, oil, 307, 430,

Ready reckoners, 46, 92

Recovering gold, 117

Bed: bronzing. 4-54. 477; coral, 478; race.

215,404: lead. ;I59, 382

Reducing leather to pulp. 22

Reed: organs, 308; organ pipes, 022;

reeds, harmonium. 69. 382

Re-enamelling zinc clock dial, 434, 618

R-rflning beeswax, 22

B'.'!locting telescope. 527, 649

Reflectors: parabolical, 623; staud, 022'

With'*, 382

Refracting telescopes. 22, 23

Refrigerators. 358, 547

Refuse lime. 311

Regihling banners, 142

Regulation of compass. 623

Relacquering brass-work, 190, 427, 431

Retnak battery, 502

Rcmanufacturing India-rubber, 202

Remelting paint, 202

Removing: fly-spots, 22: oil paint from
silk, 40, 92; paint 202, 280; plaster
from glass, 626; rust, 60; wrinkles
from prints. 500
Rendering: calico air-tight. 023; bono
seinl-transparent, 23; wood incom-
bustible, 166, 189
Repairing India-rubber combs, 239
Repiating, 382

Rcpolishing watchguards, 21, 00
Reptilos, 40

Republic of Guaiana, 202, 470 040 547

618 ''

Resin: beeswax and, 574; dissolving

502, 526
Rest, slide. 810, 334, 300. 380
Restoring Ireshness to water. 470, 501, 020
Re-tinning cast-iron. 238. 882. 404, 427
Revcrsiug: eccentric 17; engines, 478
Revolutions of blast fan, 502, 648
Revolving frame, 262, 476
lie-working vulcanised India-rubber, 400
Rhea-flbre, 94

lluumkorff's coil, 4-3. 08, 69. 142
Ring-money, Irish, 288. 280. 286; ringi!:

napkin. 480. 470; ste?m, 117

R:v-:t making. 45

Boad-nieasuring, 431,477; road-steamers,

Roarer, steamer, 22

Rocholle salt system, 239

Rocking-chair, 430

Rods: Oshing, 166, 3S2, 406, 427; fly, 287,

280; iron. 191

Rolled brass, fret-culling, 94, 117

Rollers, clolhing-iron, 21

Rolling. 167

Roman numerals, 311

Roollug, asphalte, 288, 201

Roofs, 623

Hope-bands, 118; ropes, 287, 331

Ruscoe'a lubricator. 118

Hotaliou of the earth, 190, 090, 021

Rotatory motion, 470
Round zinc wire. 287
Roundabout, velocipede, 214
Routes: overland, 22, 91; sea, 383
Rubber-valve, 622
Rubbing dowu silvered circles, 40, OS;

rubbings; coins, 527; inscriptions, 91

Rudder, sheet-iron, 118, 212

Rules: croquet, 167, 404; finding sizes of

wheels. 3H>, 856; sliding, 699; wanted,

430, 476, 499
Bust: removing, 66; in water, 113
Rusted joints, 358, 381, 405

SACKS, lifting, 69, 93, 140

Saddle-spring for veloce, 383,429; saddles.

cleaning. 280, 305, 452

Safety-valves, 214, 209, 260, 285, 287, 309

810, 350, 478, 5-17

SaleratuH, 22, 44, 68

Salmon tackle, 382,428

Sardines, 002

Sarsajiarilla, 09, 93

Saturu, 074, 098

Sauco tomato. 591.)

Sausages, 407, 018. 022

Saw: frame, vertical, 21. 110: teeth. 46.

139; saws, brazing, 308, 381; sawing

timber, 214

Scale paraffin, 262, 286
Scene-painting, 40, 68, 93; scenery Aus-
tralian, 118
Schools, continental, 406. 4:10
Science and art examinations, 675, 622 ■

science questions. 143, 188, 622

Scotch pebbles, 46, 08

Scratched object-glasses, 308

Screw: cutting, 4-5, 202, 330, 479, 525, 847,

599, 622; engine for canoe, 287, 427;

plates. 4.35, 478: propellers, 215, 260,

575; steamer, 118, 141; taps and dies,

40,3, 478, 501; tails. 4-55,478, 623; serew-

Ing-lathe, 280; screws, swaging, 333,

357

Scribbling long flccco wool, 2:18
Sculpture, 70

Sea route, 383: sea voyage, 17
Seamless felt skirts, 190; seams of macin-
tosh, 21. 67

Seasoning wood, 190

Secret code, Hogg's, 627, 590

Sections, conic. 431, 454

Securing iron cramps to stone, 455. 601

Seeds: China grass. 139; grinding, 237,

462; stock. 382. 4-53, 499. 547

Selection, uatural, 811, 499

Self-acting feed-water heator, 430,470

Semi-transparent bone, 23

Sensitive flames, 3-59, 382. 405

Separating: boos'-wax from rosin, 074;

chalk from water, 214, 833

Setting: eccentrics, 311; jewelled holes,

428

•Sewage, 238, 404

Sewing-machines. 23.8. 287. 382. 429, 430,

403. 470. 499. 002. 000, 674, 595, 096

Shapiug: ladles, 215; nuts in the lathe,

23. 43

Shafting, lining-out, 454, 547; shafts

twisting, 189, 2-59

Sheathing iron ships, 94, 140, 859

Shells: gold, 400, 595; oyster, 099; polish-

ing. 46

Sheep's: horns, dissolving. 202; skins,

colours for, 262
.Sheet: brass, stamping. 22; iron rudder,

118,212

Shilling. Oliver Cromwell. 858. 881

Ships: displacement of, 263, 334, 404. .500:

construction of. 075; irou, 622; sheath-

ing, 94, 140, 809

Shiptonian velocipede, 811

Shoes, gutta-iwrcha, 142

Shop frame, revolving, 202, 470

Shorthand. 002

Short-sight. 22, 44, 898, 821

Shot, pulling the, 478

Shovels, shaping, 215

Shower-bath. 00

Shutters, 650

Side-lever engine. 18

Sidereal limo. 308, 381

Sight, short. 22. 44. 59S, 621

Sign-writing, 382, 018

Signal, time. 288, 261

Silent fans, 202

Silica, 3S2, 453

Siliceous galena, 22

Silk-dres3lng machine. 075; silk plush,

dye for, 94; silk, removing oil paint

from. 40, 92; silk solvents. 280: silk-

winding. 351, 073; silkworms. 383, 429,

430. 476

Silver: balls, 166, 541; chlorido of, 407,

454; Coiils. 190, 213. 214, 230, 237, 2i!l,

336, 8-37, 309. asu. 331. 480. 470, 478. 624.

027. 547, 072: German, 237, 260: lead,

silver from, 60; leaf, tarnished. 94. 117;

nitrate of, 500, 573, 674, 597, 598, 020;

thimbles. 502. ,320

Silvered circle;, rubbing down, 43, 68

Silvering: diagonal planes, I Ml; el.jck-

dials, 68, 111'.. 233. 407, 627, 018

Situation of plauet.4. 190
Siw. colouring. 699, 018; sizes of: boat,
93; books, 119. 141: nozzles, 238. 309;
pulley. 48; ropes, 287, 334; wheels. 310,
334. 366

Sizing. 431)

Skat^M. wheel, 22

Sketching from nature, 166, 404, 427

Skills: dressing. 51)9: softening, 454, 490

Skirts, seamless felt, 190

Slate: cistern. 238, 404; engraving on. 22:

44.115; slates, enamelling, (.22

Slater'* specula, 239

Slide-valve, Hi. 92, 238, 2*1. 479; Blide-

rests. 310. 334. 336, 880, 022

Sliding rule. 599

Slippers, cleaning, 43

Slits in steel ganges, 358 .

Slot-cuttiug. 93. 117. 215. 237

Small: copper coin. 119, 141; furnace,

164; planing machine, 382, 622; wheels,

drying. 404, 499

Snjee battery'. 527

.Smelting lead ore, 430

Smoke: bunting. 358. 457; on walls, lis,

187; smokeless lamps, 22, 67

Soap: hard, 479; making, 287, 475, 499;

powder*, 430; soft, 68

Social BCience, 142

Soda crystals. 118, 190,451,526,571; soda-

water, 287, 310.404. 475, 499; Boda-water

bottling machine, 66

Sodium and zinc chloride, 621

Soft: metal, soldering, 311, 380; soap, 68;

waste, 94

Softening: ash timber, 359, 381; cast iron,

21. 66, 115: kid boots, 215, 404, 462;

skins. 444, 499: water. 599

Solar spectrum, 287;

Soldering 22. 67, 215, 260, 311, 358, 380

455, 500, 6(7. 599; soldering: brass, 336,

3*0; tin, 23; soft metal, 311, 380

Solid contents of cylindrical figure, 43;

solidity .if frustrum, 188

Solutions: chemical, 166, 404, 431. 477;

ethereal, 46, 68, 164; for India-rubber,

262, 286

Solvents: for marine glue, 43; for silk,

286

Soundings, deep sea, 502

South Africa, climate of, 214; South Ken-

sington examination papers, 651, 573,

597

Spaces, proportions of, 143,103. 189

Spark from induction coil, 382, 429

Speaking tubes, 600, 022

Spectacles, 311, 350

Spectroscope, 118, 287, 575

Spectrum, solar. 287

Specula: grinding, 21, 527, 023; Slater's,

239

Speculum polishing, 430

Speed of: air and steam; 23, 68; triey

cles. 309

Spelter, melting, 455, 478

Sphere, contents of part of, IIS; spheres.

turning, 465. 478, 601, 624

Sphericity of the earth, 143,165

Spice manufacture, 118

Spinning: cotton, 190, 237, 406, 478;

lathes, 526

Spiral spring. 22

Spirit level 463; spirit, methylated, 454.

477, 499, 623, 549, 671, 672. 694. 590, 618;

spirit taps, 46

Splitting: quills, 21; whalebone, 400, 499

Sponges, 623

Sportsman's velocipede, 335,337

Spot*, fly, 22

Spring bow, 69, 117; spring steel, 46;

springs: buffer, 214, 452; pendulum,

&60. 597, 619, 622; spiral. 22; voloco

saddle, 383, 429; waggon, 238

Square gaskoUng. 118

Squeezes of Inscriptions, 94

Stained glass, 22, 60, 67. 115

Staining: gut tubing linen, 426, 518,

571; paper, 95; wood, 20, 43. 66, 262

.Stains: on cloth, 358,381,405; iron, 287, 310,

3*4; nitrate of silver, 215, 260; on

steel, 622; in veneer. 358; on wood, 622

Stamping, 94; stamping: in colours,

19 ; sheet brass, 22; tea trays, 3*8

Stands: accordion. 262, 432, 640; re-

flector. 622: telescope, 216, 200, 576, 598

Stanway's velocipede. 22, 333

Star, magnitude of. 400

Starch, 699; starch and corn plant, 216;

starch manufacture, 452

Starting valve, 69, 140

Statuette, ivory, 622

Staunching timber joints, 599

Steam, 675, 620; steam: boilers, 214, 479

525: carriages, 369, 383, 622; cylinders]

fnetlon in,|406; engine, 574,598; engine,

model, 21, 143, 166, 213, 236, 454, 477;

expansion of. 699; indicator. 40 92 ■

joints, 326. 549, 671; plpo joints, 190,

'-'59; pipes, disconnecting, 43, 66; power

of, 46. »2; punching press, 527; rings

»'. 1"; roarer, 22; speed, 23, 08; vtriut

"r 375; wanted, 46, 92; water and,

143, 285; whistle, 23, 43

Steam-tight joints, 465, 478
Steamers: model paddle, 699; road, 118:

screw, lis, 141
Steaming: bonea, 478 ; bottles, 358; food

for c.ws, 203, 310; wood, 216. 237
Menl demagnetising, 470; gauges, 30s-
lead and, 358, 381; mandrels for spin-

tun? lathes, 520; melting. 40; Muihet'a,

237; needle wire, 699; ornaments, 19;

lolishiug, 214. 237, 2(10; plate, eu-

h-raved. 358. 381; plates, 527; spring, 46;

etainaon, 622; varnish for. 575; weld-

ing, 502, 648, 571; wire, 237, 355,127,

4.,T

Steering boats, 310, 380. 404

Stencil colours on paper, 117, 187 ; *tcneil

plates, 20

Stenciling oil glass, C9 91

Stereotyping. 699, 600

Sticks: emery, .'.50; walking, 399

Stitching machine. 699

SUK-k seed. .182. 453, 499, 547

Sumo: carving, 70: dressing, 287; In-
scription on. 210, 380; iron cramps in.
435. 601, 524; jelly-fish in, 179, 601; for
trinkets, 430; Turkey. 18; stones:
cutting and polishing, 09; for jewcllcrv.
215, 427

St<«il, folding, 335

Stops : organ, 287; trumpet, 623

Storm glass, Fitzroy's. 336, 357

Stoves: air. 94: gas, 69, 93, 359

Strokes of canoe, 143. 213

Strange: mechanical movomnnt, 45;

phenomenon, 479, 625

Strapping tools, 95

Straps, gutta-percha, 43

Straw and water-glass houses, 650, 019

Street telescopes, 191. 214

Strengthening steel wire. 358

Stretching gut band, 549

Strings, violin. 626

Stnhber, tree. 550

Stuff, graining. 287. 334

Stuffod birds. 238. 287, 427

Submarine lamp, 66, 118, 141

Substitute for cod-liver oil. 383, 594

Sulphates of ammonia, 22; sulphate of

atropla, 142: sulphate of copper battery,

455. 501; sulphate of load battery. 22,

67. 116. 142,188; sulphate of zinc, 166,

404,427

Summer beverages, 94,117, 140

Sun dials. 19, 118, 164. 286. 368. 62* 547,

674, 597; sun glass for telescope, 46, 92

Superficies, mensuration of, 502, 520, 548

Supply of water, 622

Supposed ancient painting, 405

Surname, changing, 575, 620

Surveying, 21

Sustaining battery. 599, 022

Swaging screws, 335. 307

Swan's process, 40, 92

Sweating of water pipes, 20

Sweet gums, 23

Swimming paddle. 623

Swivel gas joint, 622

Syphon pipes. 190 239

Syrup of hypophosphite, 262

TABLES, mathematical. 111); tables

without decimals. 203, 310

Tackle for salmon, 382, 428

Tacks and nails, wire, 190

Tall chimneys. 190, 213, 230

Tallow, 21

Tanks, alum and iron, 21

Taps: holler, 21, 44. 66: kitchen Isjilor,

570. 020; dies and, 455, 478, 001, 524,

599; spirit, 40

Tar: distillation of, 118; gas, 22, 698

021

Tarnished silver leaf, 94, 117

Tarred wood, paint for, 166, 189 230

Taste, loss of 142

Taxidermy, 22, 67
Tea: chests, 94, 117; pot, Britannia

metal, 602, 647; trays. 308; urn, 46

Teeth: affection of, 118, 141, 104; artifi-

cial, 166; of change wheels, 300; of

saw, 46. 139

Telegraphs: domestic 69; writing, 118,

187

Telegraphic books. 189

Telegraphy, 627, 572, 69(1. f.19

Telescopes: construction of, 40, 335;

Gregorian. 311; large, 142; refracting,

22, 23: stands for, 210, 200, 570, 698;

street, 191. 214

Telescopic, 22. 45, 40. 09. 92, 90, 117. 142,

143, 189, 215, 238, 260, 335, 358, 400, 002,

024. 627, 549, 660, 672. 675, 596, 022, 623

Temperament of English concertina. 002

Temperature: beneath trees, 335, 401;

unirorm, 117

Tempering: brace bits, 404. 477, 000;

buffer springs, 214, 402: drills, 19, 66,

139, 212, 230; steel needle wire, 599

Tender reet, 000, 572, 090, 019

Tent, dark, 43

Terms used iu music, 311, 334

Testing: boiler. 190, 259, 286; gold, 4011,

071; milk, 43; oil, 287, 310, 400, 453;

tobacco and mix vomica, 311, 404

Tcstril, value of, 308, 381 .

Thaumatropo, 023

Theatrical scene painting, 45, 68 92

Theino, 191, 214, 237

Theorem, 45, 92. 116'

Thermometer, 238, 260. 201, 280

Thimbles, silver, 602, 026

Thomson's road steamer, 118

Threads in ropos, 384

Throe-whcelod voloco, 262, 309, Sin, 300

Throttle valvo, 238, 261

Ticket-writing, 23, 520

Tiger, the Jersey, 602

Tightening piano pins, 382, 476

Tiles: cleaning blue, 69; colouring, 382,

403

Timber: ash, 309. 381; breaking weight

or, 69, 93; joints. 699; measuring, 20;

roofs, 623; Bawing, 214

Time, 68, 70; time-gun, electric, 020;

time, sidereal, 308, 381; time signal,

daily, 238, 261

Tin: chloride of, 190, 237; painting, 623;

tiu solder for glass, 23

Tincture of iron, 22, 44

TinfoiL alloys for. 406

Tinning and brazing, 478

Tires: bicycle, 262; India-rubber, 26;

Tobacco: fumes, 117; papors. 93; tobacco

and nux vomica, tests, for, 311, 404

Todhuntor. 383, 429, 453, 470

Tomato sauce. 099

Tonga bean-wiHwl, 430, 477

Tongue rivets fur harmoniums, 09

Toning bath, 073, 074. 697. 020

Tools: binders', an). 022; screw. 405,478,

623: strapping, 95; for swaging holts

and set screws, 330, 367; for turning

pivots, 238. 201

Tooth powder, 119. 141. 104

Tortolsesbeli: combs, 027. 649; mewliug,

00

T. >urs. pedestrian. 94, 023

Town gardening. 000, 072. 090, (119

Tracing cloth and paper, 237, 280, 309, 002.

020. 047

Transferring engravings to wood, 027, 047

Transparencies, 094

Transparent paraffin, 190

Traversing, true heart for, 675

Trays, tea. 308

Treatment or chrysalis. 382. 071

Tree-slubber, 00U; trees, temperature bo-

ueath. 335. 404

Tricycles. 43, 238. 202. 280, 309

Trigonometrical difficulty, 400, 429

Trimming cog-wheels, 94

Trinkets, stores for, 430

Trisection of angle, 142

Tropical: climate, 835; fibres, xa, 380. 018

True: heart for traversing, 070; meridian,

479, 647

Trumpet-stop, 623

Tub hooping, 622

Tubes: barometer, 22, 190, 191, 230, 310,

300, 427, 402. 498; brass, 602, 526 j eleo-

trical, 602; level, 463; Bpeaking, 600,

022; telescopes, 215, 200

Tuning: bellows for harmonium, 287,499,

660; concertina, 118; by equal tempera-

ment, 481, 477; harmonium reeds, 69;

harmoniums, £4, 407

Turbine. 92. 94. 1(10, 190, 213, 214, 216, 237,

209. 280, 311, 307

Turkey stone, 18

Turkish okc. 118. 141

Turner's Club, Amateur, 166, 189

Turning, 189, 213, 230; turning: cast-iron,

2112,310; copper. 602, 620; pivots, 238,

2(11; spheres. 465, 478,501, 624; wooden-

ware, 620, 649

Turning an harmonium into an American

organ, 674

Turpentine, adulteration of, 160, 189

Twilight and dawn, 142. 105

Twisting power of metal, 189, 259, 280

Two-manual organs, 166, 189, 213

Type, 674, 620

UMBRELLA frames, 027

Unirorm temperature. 117

Universal gas joint. 022

University examinations. 239, 261

Unsolved problems, 09, 92

Urns: bronzing copper, 699, 621; lea, 4(1

Uses of the lathe, 238, 201

VAUUUJE: in condensing engine,

478; in cylinder, 22. 44, (17

Value of: coin, 287, 475; testrll, 358, 381

Valvo facings of cylinders, 574, 020;

valves, 20, 70, 140; valves: Cornish,

311,366; rubber, 622; safety. 214,209,

260, 280, 287, 309, 310, 3.10,478. 047; slide,

40,92. 238, 280, 479; starting, 69, 140;

throttle, 2:18, 201; work on. 46

Variation of magnetic needle, 477

Varloy's patent coil, 20

Varnish, 17,45; varnishes: osphalte, 91;

for bright steel work, 070; copal, 404,

477; insulating, 002: for iron patterns,

18, 66, 91; oil, 368, 381; paper. 94

Varnishing: castings, 70; gilt mould-

ings, 09

Vegetable gas, 308

Veloco. three-wheeled, 2112. 3(19. 310, 300

Velocipedes, 07. 90. 140,202: velneii>edes:

'■ Eilinhurgh," 262; "English," 142,

188, 190; Lain home's, 430, 647;

"Loo's," 160; motivo power for, 479;

roundabout. 214; saddlo spring for,

383, 429: "Sulptonian," 311; sports-

men's, 335, 357; Stanway's, 22, 333;

water, 287, 331: wheels fur. 94, 333

Veneer, stains on. 358; veneora for har-

monium pans. 213

Veneering. 19. 21. 238

Ventilator for chimney, 100

Venus, 94, 142

Verge watches, 599

Vernier, 382

Vertical: engines, 430,470; saw frames,

21, 110; slide rest, 622

Vessel propelled by windmill, 500, 073.

090. 019; vessels: galvanised, 30S, 381;

model, 119, 138

Vesuvians, 026

Vice-box. worm for. 40. 92

Views, dissolving, 33S, 407

Vinegar. 308, 381, 382, 405, 428, 429

Violet ink, 46, 92, 118

Violin, 40; violin strings, 527

Voice, loss of, 575

Voyage, sea, 17

Vulcanised india-rubber, 118, 141, 214

237. 400. 600

Vuleaniser, 311

Vulcanite, polishing, 21, 573, 690

WAGGON springs and axles, 238

Walking tour, 94; walking-stick air

gun, 238; walking-sticks, polishing, 599

Walls: damp, 380: decoration of, 4:10;

papers for, 330. 380; smoke, ou, 118,187

Walnut stains, 262

Wampum money. 22, 44

Wont of pressure, 430

Warming by hot water, 309

Warped cabinet lid, 4(«1. 470, 023

Washing blue, 44; washing-machine, 40,

382, 429

Waste, cotton, 19 ;|wastc, Bolt, 91

Watch: cases, enamelling, 649; cloaning.

210. 237; guard, ropolisbing, 21, 00;

making. 214, 308, 3811, 382; pendulum

spring lor, 697, 619. 022; pivots, 166,

209: for railway guards, till, 357. 380;

wheels and pinions. 478; watches,

keyless, 70; vergo. 699

Water, 46; water: analysis, 238, 280,

311. 380; in baths. 118; chalk and, 214.

333; colours, 001; condensing, 464;

conveyance, of, 009; distilled, 330, 308,

380; filtered, 479, 601, 625; rorcing, 202,

402, 470; hard, 119; Insects in. 404:

meters for, 166. 470; motion of, 18, 40,

92,116,139 ; pipes: sweating, 20 ; power.

43. 40. 66, 68, 92, 139, 074, G22; pressure.

074. 098, 020; pump, 308, 381 ; raising,

40, 92, 143, 432; rust in, 118; soda. 287.

310, 404. 475. 499; softening, 599; steam

and, 143, 286; supply, 022: velocipede,

2K7, 334; weight of, 117, 14", 164, 238,

201, 309. 300

Water barometer, 479, 502, 020, 070

Water-gilding. 406

Water-glass, 478, 601; water-glass and

straw houses, 560, 019

Watering garden, 287, 334

"Waterproof, 430, 376; water-proor glue,

21; waterproofing: calico, 623; cloth,

238. 261. 285; paper, 118, 141, 167;

timber roof. 023

Waters, aerated, 330, 026

Waterwheels, 358, 382, 428, 573, 594, 019

Waterworks, 575

Wax bleaching. 45

Waxing engraved brass plate, 94

Weak eyes, 450, 477, 001.

Weaving. 431

Wedgwood plaques, 70, 93

Weights of: ball, 002, 020, 648, 501, 690,

097; chemical solutions, 431, 477;

frustrum, 142. 160. 188, 213, 236; gas,

286; metals, 601, 619; rails. 627, 096,

019; water. 117, 140, 164, 238, 261, 309.

303; wire, 622; wrought-imn gates, 46

Welding: cast steel, 602. 548, 071; forks,

074

Wenham's parabolical reflector, 023

Wet rags, 142

Whalebone, splitting, 406, 499

Wheel: cutting, 19. 216. 237. 262 ; gearing

310. 366. 380; making, 142; skates, '.'_>;

turbine, 190, 214, 259, 285

Wheels: bicycle, 44, 142, 188; change,

454. 000, 000. 072, 675. 620; cog. 94;

drying small, 454, 499; emerv. 498;

fly. 93, 191, 214; sizes of. 310. 334, 306;

velocipede. 94. 333; watch, 478; water,

308. 382, 428, 073. 094, 019

Whistle, steam, 23, 43

White : brass, Parsons's, 311; coral, clean-

ing. 166, 330, 380; flint, 382. 463; fur-

niture cream, 479, 025; metal bearings,

18: metal, hard. 000; paint, 202, 462

Whitoload. 262. 402

Wind: the east. 23; instruments. 09

Winding: drums, conical, 262, Oy'.l; silk,

001. 073

Window: frame, revolving 262, 470;

painting. 202, 280

Windmills, 69: windmills: model. 623;

for propelling vessels, 000, 073, 090, 619;

Tor working lathe, 431

Wines, 202

Winter's electrical machine, 47

Wire : binding magnetic, 070; colouring,

308. 381; covering, 46, 215; joining.

4-1, GO; needle, tempering, 099; netting

machine, 382; stool. 237, 308, 427, 470;

tacks and nails, 190; weight or, 622;

zinc, 287

With's reflector, 382

Wood engraving, 202, 027; wood and
iron, protecting. 70; wood and mouU
cutting machine. 22 ; wood, transferring
engravings to. 027, 647

Wooden: handles in lathe, 142, 105, 188;
ware, turning. 02G. 349

Woods: Bankal. 94, 117; dyo, 502;

feathers In, 17; foreign, 623; green-

heart, 550; inlaying fancy, 107: pine,

21; rendering incombustible, 160, lH'.i;

seasoning, 190; stains in, 022; staining.

20, 43, 60, 202; steaming. 210, 287;

tarred. 100, 189, 230: Tonga bean. 430.477

Wool. 21; wool: scribbling, 238; yarns

and, 001

Woollen carpets, 308

Work : carpenters', 18; mill and forge, 107

Works : on China grass, 22; clerk of, 19;
on cotton, 600; on electricity, 40, 08. 09,
110; labourers', 70. 93; medical. 70. 9,1;
on projection, 188; 011 soap-making,
287, 470, 499; on valves. 40

Working latho. 431; Working Men's Ex-
hibition, 21, 44

Worm for vice-box, 40, 92; worm-eaten

organ barrels, 287, 428

Wrinkles In prints, 699

Writing: ink. 478. 501. 502. 524. 520, 548;
on glass, 09. 93, 116. 142; Bigns, 382.
018; telegraph. 118, 187; tickets, 23,52(1

Wrought-iron gates, 46

YACHT-BUILDING, 28, 45, 218

Yarn, hosiery, 22; yani:<, dyeing, 001

Yellow-dye, 287, 452

ZEALAND, New, 118

Zbic: ashes, 21; clock-dial 404. 018;

plant, 20, 66; plate for battery. 20;

sodium chloride and, 621; sulphite of,

166,404.427; wire, 28T

Zoophytes, 002

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THE

ENGLISH MECHANIC

AND MIRROR OF SCIENCE AND ART.

OURSELVES AND OUR SUBSCRIBERS.

As promised last week, the English Mechanic And Mirror Of Science appears this week in an enlarged size and an altered form. In putting the advertisement pages outside, we have acted in obedience to a generally expressed wish on the part of our subscribers. No doubt the publication will be subject to some disadvantages from this change, as it will be less exhibited in shop windows.snd will thereforebeless under the eye of the passing public. On the other hand, our subscribers, as we intimated last week, will derive decided advantages from the alteration, and they may easily make up for any disadvantage we may suffer by introducing the work to an enlarged circle of readers.

W e have increased the size of the paper because Nee desire to satisfy the largest number of subscribers. Some may say, Why not increase the number of pages, instead of increasing the size of the pages? Our answer is, Because increasing the number of pages involves the necessity of double machine labour, and consequently double expense. When we have from time to time given a Supplement of Eight Pages, it has cost us nearly as much for machine work—that is, for working off the sheets from the type, as we have paid for machining the ordinary impression of thirty-two pages; or, in other words, it costs as much to work off a small sheet as a large'one. As it became necessary to give additional space, it was also necessary that the size of the page should be increased.

During the past fortnight we have received, in

response to our invitation, many suggestions for

the improvement of our Journal, with some of

which we shall comply. More than one has

suggested that the contents of each number be

placed on the outside page. This we have done.

As it may be expected, different readers and

correspondents are desirous that their favourite

subjects should receive more especial treatment.

If we complied with such requests we should favour

some at the expense of others, and so to some

extent prevent the primary object we have in view

—that of providing the largest amount of useful

information for the largest number of readers.

It should, however, be borne in mind that

the English Mechanic is to a large

extent what its correspondents make it. Its

subscribers may be considered as members

of a vast mutual improvement society, who

consider it a duty or a privilege to instruct

each other. One person asks for information on

some particular subject, and another person,

several hundred miles away, it may be, sends it,

not only without fee or hope of reward, but at his

own expense. He, however, has the satisfaction

of knowing that his letter, suggestion, or recipe

may be of benefit to thousands besides the one

who specially asks for the information. The

English Mechanic is therefore a reflex of the intelligence and the generosity of thousands of subscribers. Its contributors are numbered not by units, as in most publications, but actually by thousands. Each one contributes according to the wealth of his intelligence, or his desire to impart it to others. Any one who has listened to debates in mutual improvement societies, at an educational or scientific conference, or in Parliament, knows the standard of eloquence varies with the speaker. Some speakwell.and tothe point, and others occupy time to very little purpose; say what others have said before them, and in a less effective way, or say things that are erroneous. It is pretty much the same in our English Mechanic's national improvement society. Some correspondents write about what they thoroughly understand in appropriate language; others are less fortunate. They either ask questions which others have asked before, or go over ground which others have trodden with more effect. But woe betide them if they make mistakes. Then a half a dozen are ready with pen and ink, not as they say in the House of Commons, to catch the Speaker's eye, but to seize the Editor's attention, in order to correct the mistake.and rebuke, not always in the most parliamentary language, the offender. Sometimes a comparatively puerile question evokes an elaborate reply, or an incorrect answer leads to an interesting controversy. This picturesque variety constitutes the chief charm of the English Mechanic. In the House of Commons, any member has the right to ventilate his own opinions on any special subject, and we have frequently been surprised to see a poor speaker on his legs "in that oldest temple of freedom in the world" speaking in a prosy manner to almost empty benches. Take away his right to do so, and you immediately vitally impair the value of the house as to consultative and representative assembly. As in the House of Commons so in the English Mechanic. Sometimes, it may be, a somewhat illiterate man asks »hat may be supposed by many readers an unimportant question. But it is not unimportant to the askcr, and possibly to thousands of others similarly situated. If, then, the well-informed will be tolerant of the ignorance of their brother readers, sympathise with them, and do their best to enlighten them, the fundamental purpose of this journal, under, its present management, will be answered. Every correspondent may contribute something to the common stock for the common good, and by so doing he will in no way itnpoverisli himself, but do something towards enriching all.

Several years since, when passing through the streets of Liverpool, we were accosted by a pretty little girl. We shall never forget her bright blue eyes, and her hair, which fell like woven sunbeams over her shoulders. This pretty little

creature asked us, of all things in the world, to buy a brick, showing us at the same time a small engraving of a brick on a card. We asked her what she meant, and she said they were about to build in some part of the north of England a temperance hall, and that it was computed that each brick in the building, and the labour of putting it there, would cost about a penny, and she wanted us to assist to build the hall to the extent of a single brick. Did she possess fewer oharms, and speak less musically, we should have bought a brick. As it was, though pennies were of some importance to us then, we bought more than one, and have the satisfaction at this moment of remembering that we assisted in a very small way in raising a temperance hall. So it is with the contributors to the English Mechanic. Each one, by replying to a single query asked by a brother reader, contributes h is brick to the Temple of Knowledge. Our readers will be glad to know that for some time past the English Mechanic has been increasing its circulation and its influence week by week. It circulates at the present time not only more than any scientific publication in thiscountry, but more than all of them put together. This is authoritatively stated. It is right that our correspondents should know to what a large number of readers they speak, and that our advertisers should also know to what a large constituency they appeal.

TIME.

Br A Fellow Op The Royal Astronomical Society.

(Concluded from page 649, Vol. X.)

WE must, however, return to the Transit itself, the use of which, as tho reader will be by this time prepared to learn, is toobservethe pas8age\>fCelestialo"jectsover the Meridian, either for obtaining the time or determining what is called Right Ascension. The way in which observations are actually made is this. Just beforo the expected time of transit of any given star, the telescope is elevated, by means of its altitude circle and level, to the height proper for its perception. Now what the observer has to do is to note with all imaginable accuracy the instant of the star's passage over each of the wires, and this he dons by listening to the beats of the clock while • regarding the star, and we now see the importance of the clock having a clear sharp tick. As it will very rarely happen that the star exactly on a wire at the exact instant of the i.vk°» beat, we have to estimate tho fraction of' -•'• _nd This is done by comparing its dist- in the wire at the beat before it crone it, with '.' distance at the beat after it crosses it. Ri oreiuv to Fig. 6 will explain this.

Remembering that as tho tela"'op > "W." stars seem to come into the . i.l i.t right-hand side, and to leave it on tbo '■' if we imagine that, in the '^ure, a

having entered at the righlhand side is at a at the 17th second of any given minute, and at b at the 18th, then we should estimate that it was on the wire itself at 17'8s. Or, again, if it were at c at 52, and at d at 53, we should put down its timeof crossing the wire as 52 5s., and evidently the higher the power employed, the more rapid will be the apparent motion of the star, and the nore accurate these subdivisions. The object of observing stars between the two horizontal wires is that all transits should be taken over the fume partt of the vertical ones. Supposing, then, that the hour, minutes, seconds, and fraction of a second at which one star was upon each of the five wires is noted, all we shall have to do is to add the fire observations together and divide the rmilt by 5 to obtain the instant of the star's passage over the central wire, which, if the instrument be in adjustment, will coincide with the meridian. In the case of the Sun, Moon, and Planets, which present sensible discs, as of course it is the passage of their centra over the Meridian which is the phenomenon to be observed, the mode adopted being to take the time of passage of the west or preceding limb over all the wires, and then to do the same with the east or following limb, the mean of these two sets of observations being evidently the instant of the transit of the centre or the body we are observing. The " Nautital Almanac" givses the Right Ascension (or distance in sidereal time eastwards of the Vernal Equinox or first point of Aries) of 148 standard stars, as well as that of all the members of the Solar System; so that, as our Sidereal Clock marks, or should mark, Sidereal Noon, or0h.0m.Os. when this first pointof Aries is on the Meridian, we have only to compare the observed time of passage of any given Star, &c, with its Right Ascension, as given in the "Nautical Almanac," to find out the Error of tho Clock. It will further be instantly seen that a comparison of the Clock Errors day after day will give us the Clock Rate. An actual example of a transit, taken at random from our Transit book, under the date of the 9th of October, 1809, will exemplify a good deal that we have been saying :—

a Cygni

1st wire

2nd

Centre 20

4th

5th

Apparent Transit of a Cygni 20 37 3610

True Right Ascension 20 36 5'J 72

Meridian. Turning this into Solar time by the aid of the table on pp. 506 and 607 of the "Nautical Almanac," we shall have the instant which a good clock, regulated by Mean Solar time, should indicate when our star is on the middle wire of the Transit. Supposing that our reader has the "Nautical Almanac" for this year before him, we will illustrate this rule by a couple of examples—and, first. At what hour will n Ursa? Majnris South on the night of the 12th of March at Greenwich? We find on p. II. of the month of March, that on the day we h»ve selected the Sidereal time at Mean Noon is 23h. 19m. 4328s. Turning, now, to p. 3C4, we see that the Right Ascension of n Urseo Majoris at the same date is 13h. 42m. 26 04s. Adding, according to the precept, 24 hours to this, we get 87h. 42m. 26 04s. Then subtracting from this the Sidereal time at Mean Noon—thus:

n. M. B. 37 42 2604 23 19 9328

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Clock Error

+ 30-38

It will be noticed that instead of adding up the whole of the five observations, and dividing the result by 5, we have merely added the seconds

2

togetherand multipliedtliercsultby 2 ; — of any

10 1 thing being obviously — of it. Tho only precau

5 tion necessary is to add or subtract as many fifths of a minute, or 12 seconds, as shall make the result correspond with the number of seconds shown at the middle wire; beeauso in reducing a really good observation, the decimals of a , second are all that wo need take account of.

It may however, have occurred to any one who has carefully followe'd us so far, suppose that wo do get the exact error and mte of a Clock, as far n» Sidereal time is concerned, what use can we I mike of this when wo have got it? Well, Mean! Hl lar time can, hy an easy process, be derived immediately from Sidereal ; but perhaps thesimplest way for a beginner is to compu'e the mean time of Southing of the object he proposes to observe; • I.." can then compare its transit directly with «li'f" :'nary Clock. This is most simply effected by !'• I .< iwingrulc. Erom the Right Ascension ofthe sta planet, as the case may bo (adding, if

ji!-:;cf-.i"y, 24 hnnra), subtract the Right Ascen.;>»n'of tlie Sun at tho previous Mean Noon, «iven in the '•Nautical Almanac " at p. II. of •tit} month rider the head of " Sidereal Time at Vaj Noon." The remainder will be the Sirte'1 I'miss, minutes, and seconds after Mean Noon it 1. uieh the body in question will cross the

we finally obtain 14h. 20m. 214252s. as the mean time of transit of the Star referred to, or the instant which a good ordinary clock ought to indicate as r\ Ursa? crosses the middle wire. This will be seen to be 2h. 20m. 21'4s. after midnight on the 12th of March. Or, again, What will be the mean time of transit of Sirius on the 11th of April 1 From the Right Ascension of Sirius, 6h. 39m. 2482s., we take tho Sidereal time at Mean Noon, lh. 17m. 5985s. ; we get 5h. 21m. 24-97s. Converting this as before into Mean time we obtain 5h. 20m. 32-3Is. as the instant by a gooil ordinary clock or watch that Sirius will be on the Meridian. We may obtaiu tho clock rate without any reduction of the observation, if we bear in mind that any given star ought to return to the Meridion after an interval of 23h. 56m. 4"09s., as shown by a clock or wa'ch indicating ordinary or Mean time. We believe there is a little book just pub ished calhd " How to keep the Clock Right," the author of which we fancy must proceed upon this principle of observing this interval of 23h. 56m. 4 09s. between the successive returns of any particular star to some fixed point in the Heavens; but we have never seen it.

Into the adjustment of the Transit and the corrections to be applied to its indications, we shall not here enter. Should the want of information on these points be felt, and the desire for it bo expressed, we might Bt some future time perhaps, enter fully into detail on this subject. As it, is, we fed that in giving directions for making these adjustments and corrections, we should be addiessing a very limited public indeed, and occupying precious space, which we have already considerably trenched upon. Our present, and we would fain hope not wholly unsuccessful, endeavour has been o present in a simple form an e position of the mode in which the succession xf natural phenomena is made subservient to the purpose of the equable subdivision of Time ; and so, more by the method of illustration than in a merely didactio woy, to remove some of the vagueness which attaches to popular conceptions on this Bubj ec-t.

ON THE PHENOMENA OF COMBUSTION.

BJJECIAL REPOHT.

ON Monday evening, March 0, in the Lecture Theatre of the Society of Art*, the first of a series of four Cantor Lectures on Combustion was delivered by Dr. Benjamin Paul, F.C.S. He first showed that combustion was generally a

chemical action inv. lung the union and material alteration of two substances with which we were familiar in the use of fuel and in tho production of li^ht; was a cause of oxidation, the one material being yielded by fuel and oil of tallow, and the other being furnished by the atmosphere. The second point to which he called attention was that combustion took place in several different forms; that there were several conditions essential for active combustion or burning; that two of the most prominent effects of combustion were the evolution of heat and light, and then there was between all the phenomena attending combustion, a quantitative relation which was constant and uniform—that is, the relations between the quantitie-i of two materials uniting in such a wav as to constitute combustion, and the quantity between the materials uniting and effects produced, either the amount of heat generated by their union or between tho quantities uniting, and some effect due to the heat produced by them. Lastly, he pointed out that there was a difference between the temperature and the quantity of heat contained in matter.

The precise title of tho second lecture, delivered on Monday, the 13th inst., is as follows :—" Use of fuel for domestic purposes, as a source of motive power, for industrial operations not requiring intense heat, distillation, evaporation, Ace., and for producing cold; varieties of fuel." The lime at the disposal of the lecturer did not allow of his dwelling upon all these topics iu detail, but after some general remarks, he proceeded to observe that temperature could only, in a certain limited sense, be taken as measure of heat. The use of coal for domestic purposes had only become general during the last hundred or hundred and fifty years; and although the means of using it were considerably improved, yet many of tho fire-places now in use were very defective, inasmuch as the greater part of the heat produced from the fuel was wasted. In a mass of fuel in a state of bright glow, the quantity of heat that was radiated in the same manner that light was diffused, varied from about a quarter to one-half of the whole. In many (ire-places, a great deal of heat, instead of being radiated into the room, was radiated up the chimney. Great economy, as for as fuel was concerned, was effected by the use of close stoves, which, on the Continent, especially in Germany and France, was almost universal. By the use of these stoves, a small amount of fuel sufficed to keep apartments warm. Similar stoves had been introduced into this country by Dr. Arnott, but had never found much favour with the Euglish. Although chimneys were universal here, they were by no means so in-all parts of Europe. In certain parts of Italy and Greece hut few of the houses had chimneys, the only means of warming rooms being by open braziers, like those used by the ancient Greeks and Romans. This mode of burning fuel was open to the serious objeotion that the air beoame vitiated, owing to no mode of escape being allowed to the carbonic aoid gas. After describing some of the more recent improvements made in fire-places, the lecturer offered a few remarks upon the use of gas tor domestic purposes. The recommendations in favour of gas were convenience, cleanliness, readinessfor use as well as for being lispensed with. Yet, notwithstanding these recommendations, it must be always regarded as a very dear kind of fuel when compared with coal or any fuel of that nature. Speaking next of fuel as a source of motive power, the lecturer remarked that this was undoubtedly one of the most important of all the uses to which fuel could be put. Its use in this respect was based upon the principle that heat being itself a condition of energy was capable of being converted into mechanical force. It was chielly through the medium of water transformed into vapour that this motive power was produced. In this case, the heat generated by combustion wasexpended in vapourisingthe water, and in such cases there was n d' finite relationship between the quantities of heat expended and of water vapourised. Every pound of boiling water required 966 units of l»at for converting it into steam, or just five and a third times as much heat as was requisite to raise the temperature of a pound of water from the freezing to the boiling point. The lecturer then olludcd to the relationship between hat and mechanical energy, and in doing so briefly traced thehistory of the mechanical development of heat from the production of

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