To Refine Oil for Fine Mechanism.—Add equal parts of lead and zinc shavings to best olive oil, and leave it in a cool place until the oil becomes colourless.

Waterproofing Canvas.-Water, 1 pint; hard yellow soap, 6 oz.; when boiling, add 5 lb. boiled linseed oil and lb. patent dryers. Another method is to steep the canvas first in a solution of water, with 20 per cent. of soap, and afterwards into a solution containing 20 per cent. sulphate of copper.

Waterproofing Calico.-Boiled linseed oil, I quart; soft soap, 1 oz.; beeswax, 1 oz.; the whole to be boiled down to three-fourths of its previous quantity. Another method is-hard yellow soap, 4 oz., cut into shavings, and beat with sufficient water to the consistency of cream; then stir it well into pint boiled linseed oil. Apply with a brush on one side of the calico only.

Tarpaulin Dressing for Waterproofing Sheets for Railway Wagons and Carts, &c.-Linseed oil, 95 gallons; litharge, 8 lbs.; umber, 7 lb.; boil for 24 hours, and colour with vegetable black, 8 lbs.

Waterproofing Brick Walls.-Soft paraffin wax, 2 lb.; shellac, lb.; powdered resin, lb.; benzoline spirit, 2 quarts; dissolve by gentle heat in a water bath; then add 1 gallon benzoline spirit; and apply warm. Being very inflammable, keep it away from fire.

Waterproofing Woollen Cloth.-Mix lb. alum and lb. sugar of lead in 2 gallons of rain water; stir up repeatedly at intervals during 3 hours; then allow to settle, and pour off the clear solution, in which immerse the cloth for 24 hours; after which let the cloth drip and dry, without wringing. Another method is to dissolve equal parts of isinglass, alum, and soap in water; each to be dissolved separately, and then all welb mixed together; brush the solution on the wrong side of the cloth, and dry; afterwards brush the cloth well first with a dry brush, and then brush lightly with a brush dipped in rain water, and dry. Another process is:boil the cloth in a solution of water, 1 gallon; soap, 2 oz.; glue, 4 oz., for several hours; afterwards wring and dry; and then steep for 10 hours in a solution of water, 1 gallon; alum, 13 oz.; salt. 15 oz.; wring and dry at 80° temperature.

Waterproofing Packing Paper.-First dissolve 1 lb. of white soap in 1 quart water; next dissolve 2 oz. of gum arabic and 5 oz. glue in a quart of water; mix the two solutions and heat; soak the paper in the mixture and hang up to dry.

Waterproof Dressing for Leather.-Beeswax, 1 oz.; powdered resin, I oz.; soap, 3 oz.; castor oil, 1 pint; boiled oil, 1 quart; boil, and afterwards thin to proper consistency with warm oil of turpentine.

Mixture for Preserving Leather Belts.-First wash the belt with warm water, and apply a mixture of castor oil, 2 quarts; tallow, 1 lb. ; pow. dered resin, 1 oz.; hard soap, 2 oz.; melt and mix.

Dubbing.-Black resin, 2 lbs. ; tallow, 1 lb.; train oil, 1 gallon.

suet.

Razor Paste.-Mix equal parts of jewellers' rouge, blacklead, and Another receipt for the same purpose is―Levigated oxide of tin or putty powder, 1 oz.; powdered oxalic acid, oz.; gum, 20 grains.

Non-conducting Material for Clothing Steam Cylinders and Pipes, to prevent Condensation.-Silicate cotton.

To Harden the Surface of Wood Pulleys.-Boil them for 10 minutes in olive oil, and allow them to dry.

To Clean and Whiten Marble.-Make a paste of equal parts, whiting, pearlash, and dry soap; cover the article thickly, and allow the paste to remain on for 14 days; then wash off with a sponge and water.

Imitation Beeswax.-Melt and mix, solid paraffin, 60 parts; yellow resin, 40 parts.

Ink for Marking Packages.-Boil 2 oz. shellac and 2 oz. borax in 1 pints of water until they are dissolved; then add 2 oz. gum arabic; when cold, add lamp black or Venetian red to the proper colour. Keep the ink in a bottle.

To Resharpen Files.-Old files worn too thin to recut, may be resharpened thus:-Clean the file by immersion, first in spirits of turpentine, and next in clean warm water; then place the cleansed file point downwards in a jar containing a solution of-nitric acid, 1 pint; sulphuric acid, 1 pint; water, I quart; and allow the file to remain in the solution, for an hour or more, according to the depth of teeth.

To make Small Artificial Stone Articles.-Reduce the stone to very fine powder, and mix it with as much fine soapstone as will make a thick dough; place the dough in a mould, and subject the same to a good pressure; after leaving the mould, bake the article in an oven.

Steam Joints made with Indiarubber.—Where indiarubber is used to make a steam joint-such as the joint of a mud-hole door-the indiarubber, as well as the faces of the joint, should be covered with a mixture of-tallow, I part; blacklead, 2 parts; which greatly adds to the efficiency and durability of the joint.

To Take the Sulphur out of Coke.-Water it with salt and water.

CEMENTS FOR THE LABORATORY AND WORKSHOP.

Acid-proof Cement.-Mix a concentrated solution of silicate of soda, with powdered glass to form a paste.

Aquarium Cement.-Mix white lead, red lead, and boiled oil together, with gold size to the consistency of putty. If required to be dark in colour, mix lamp black with it.

Another Aquarium Cement.-1 gill, litharge; 1 gill, plaster of paris; 1 gill, fine dry white sand; and 3rd gill each of powdered resin and red lead; mix into a stiff putty with boiled oil, to which a little gold size has been added.

Waterproof Cement.-Powdered resin, 1 oz., dissolved in 10 oz. strong ammonia.

China and Earthenware Cement.-Dilute white of egg with its bulk of water; mix to the consistency of paste with powdered quicklime.

China and Earthenware Cement.-Dissolve isinglass in hot water, and add acetic acid.

Another China Coment.-Finely powdered glass, mixed with white of egg.

Office Paste.-Strong, and does not soon turn sour: solved in 1 pint of water; add flour, and when boiled, add again boil until properly dissolved and mixed.

oz. alum, disoz. resin, and

Electric Cement for fastening Brass Work to Glass Tubes.— Resin, 5 oz.; beeswax, 1 oz. ; red ochre or Venetian red in powder, 1 oz. Fire-proof Cement.-Linseed oil, 4 oz.; handful of quicklime powdered; boil till thick and cool and harden; then dissolve and use in the same way as ordinary cement.

Elastic Glue.-Dissolve glue in a water bath; evaporate to a thick fluid, and add an equal weight of glycerine; cool on a slab.

Liquid Glue.—White glue, 16 oz.; dry white lead, 4 oz.; soft water, 2 pints; alcohol, 4 oz.; stir and bottle while hot.

Another Liquid Glue.-Glue, 3 pints, softened in 8 parts water; add pint muriatic acid and pint sulphate of zinc; heat to 176° F. for 12 hours; then allow it to settle.

Cements to resist Sulphuric and Nitric Acids.—Silicate of potash (30° Baumé) and powdered pumice; or powdered asbestos 2, sulphate of baryta 1, silicate of soda 2 (50° Baumé, or 130° for dilute acids). For hot nitric acid, silicate of soda 2, sand 1, asbestos I.

Marine Glue.-Pure india-rubber, 1 pint, dissolved by heat in mineral naphtha; when melted add, shellac, 2 pints, and cool on a slab.

Marine Glue, another.-Glue, 12 pints; water to dissolve, and yellow resin, 3 pints; melt, add turpentine, 4 pints, and mix.

Portable Glue for Draughtsmen.-Glue, 5 oz.; sugar, 2 oz.; water,

8 oz.; melt in water bath; cast in moulds; and dissolve for use in warm

water.

Portable Glue for Thin Paper.-Gelatine, 1 lb., dissolved in water, and water evaporated till nearly expelled; add lb. brown sugar, and pour into moulds.

Glue for Damp Wood.-Soak glue in water until soft; then dissolve in smallest amount of proof spirit by gentle heat; in 2 lbs. of the mixture dissolve 10 grains gum ammoniacum, and while liquid add half a drachm of mastic dissolved in 3 drachms rectified spirit.

Glue to resist Damp.-Boil linseed oil with ordinary glue.

Gum for Paper Labels.-Dextrine, 2 oz.; acetic acid, I oz.; water, 5 oz.; alcohol, 1 oz.; add the alcohol to the other ingredients when the dextrine is dissolved.

Cement for Papier Mache, Cards, &c.—Dissolve isinglass in alcohol and add sufficient rice flour to thicken; warm gently, and add a small quantity acetic acid.

Tough Cement for Paper, Cards, Linen, &c.-Mix 8 oz. rice flour with cold water; simmer gently, and then add 2 oz. glue dissolved in water, and alum 1 oz.

Tough Glue Cement.-Soak Russian glue for 12 hours in cold water; pour off the water, and add sufficient glacial acetic acid; dissolve in a hot water bath.

Glue to resist Moisture.-1 lb. glue melted in 2 quarts skimmed milk.

Glue to resist Moisture, another.—1 glue; 1 black resin; red ochre; melt and mix.

Thick Glue Cement to resist Moisture.-Shellac, 4 oz.; borax, 1 oz.; boil in a little water, and concentrate by heat to a paste.

Tough Glue Cement.-To ordinary glue add part vinegar and a littleglycerine; mix plaster of paris with it to the required consistency.

Cement for Parchment and Card Board.-Powdered Chalk and a little glycerine mixed with common glue.

Litharge Cement.-Litharge, 1 oz ; plaster of paris, 1 oz.; powdered resin, oz.

Cementing Metal to Glass.-Copal varnish, 15: drying oil, 5; turpentine, 3; melt in a water bath, and add 10 parts slacked lime.

Cementing Metal to Glass; another.-Mix 2 parts powdered litharge and 1 part white lead; mix 3 parts boiled linseed oil with 1 part copal varnish, and stir the powder into the liquid.

Cement for Joining Metals to Wood.-Dissolve in boiling water, glue, 2 lb.; gum ammoniacum, 2 oz.; adding, in small quantities, 2 cz. sulphuric acid.

Cemont for Joining Metals to Earthenware.-Washed fine sand, 20 parts; litharge, 2 parts; powdered quicklime, I part; mix with boiled. linseed oil, and colour with any pigment.

Cement for Iron Stove Pipes and for filling Cracks in Stoves.— Equal parts pulverised clay and fine wood ashes, and a little salt; mix with water to the consistency of putty.

Cement for Stoves and Ranges.-Mix fire clay, with a solution of silicate of soda.

Cement for Chemical Apparatus.-Melt and mix starch, glycerine, and gypsum to required consistency.

Cement for Joining Metals to Bone, Ivory, and Wood.—Mix litharge with glycerine to the required consistency.

Cement for Leather, Canvas, Cloth, Parchment, &c.-Melt and mix glycerine with glue.

Cement for Thick Leather.-Melt and mix glycerine with glue, and add pure tannin to proper consistency.

Pale Tough Cement.-Dissolve 75 parts of white indiarubber in 6 parts chloroform, and add 15 parts mastic and a little glycerine.

Forcelain Cement.—Add plaster of paris to a strong solution of alum. Cement for Fastening Metal Tops on Oil Lamps.-5 parts water, boiled with 3 parts resin, I part of caustic soda, and mix with half its weight of plaster of paris.

Cement for Fixing Brass Letters on Glass.-Copal varnish, 15 parts; drying oil, 5 parts; turpentine, 2 parts; liquified marine glue, 5 parts; melt in a water bath, and add 10 parts dry slacked lime.

Tough Cement for Various Purposes.-Guttapercha, 1 lb.; indiarubber, 4 oz.; dissolved in bisulphide of carbon; pitch, 2 oz.; shellac, 2 oz.; boiled oil, 2 oz.; melted together.

White Cement for Shells and Various Purposes.-Best gelatine, 1 oz., dissolved in water; then add drachm glacial acetic acid and a small quantity of powdered and sifted calcined oyster shells.

Cement for Coating Acid Troughs.-Melt together, 1 part pitch, 1 part resin, and 1 part plaster of paris.

Thick White Cement.-Resin, 4 oz.; beeswax, 1 oz.; plaster of paris, 5 oz.; borax,

oz.

Cement for Fixing Iron Bars into Stone.-A compound of equal parts of sulphur and pitch.

Indiarubber Cement.-Dissolve 2 oz. of pure white raw indiarubber inpint benzoline or bisulphide of carbon; heat in a hot water bath.

Cutlers' Cement for fastening the Blades of Knives into Handles. -Resin, 4 parts; beeswax, I part; brickdust, I part. Another cement for he same is: resin, 4 parts; pitch, 4 parts; tallow, 2 parts; brickdust, 2 parts.

oz.

Cement for Box Wood and other Hard Woods.-Dissolve isinglass in alcohol; and mix sugar, oz.; box wood filings, 1 oz.; and add a little acetic acid.

Cement for Cementing Emery to Wood.-Melt and mix equal parts