THE launching of the

caisson for the Brooklyn terminus of the East River Bridge, says the Scientific American, which was quickly and easily ac complished on the 19th March of the present year, was considered a noteworthy feat of engineering.

Our engravings show the caisson on the ways, as it appeared when ready to be launched, and also some details by which the construction of the ways and the plan of procedure in making the launch may be comprehended.

The structure was put together with its longer side parallel to the river bank, and about 100ft. distant from it, and the ways upon which it rested were seven

in number, and each about 180ft. in length. These ways were laid in such a manner that their apper faces were curved to a radius of about 312ft., and at a slope which made the chord of this arc form an angle of about 5°, the curved sine of the arc being some 13in., and the upper ends of the ways 15-6ft. higher than the lower ends. By this means an accelerated motion was given to the caisson in the latter part of its transit; the increased velocity it thus obtained enabled it to overcome the great resistance it encountered from the water when it struck the river broadside on. The details show the form

These ropes being cast off simultaneously, the
cams were thrown over, and the caisson was free
to move equally throughout its length. The posi-
tion of the caisson upon the ways when ready for
launching is clearly shown in the figures. The
position of the air chamber is indicated by the
dotted lines, H K L, and at E is shown a partition,
which was constructed to divide the air chamber,
and prevent the air from any sudden movement
from one part of the caisson to another, which
would have affected its stability. The dotted lines
CD show the position assumed by the structure
just as it left the ways, and E F represents it after

given to these ways, and it will be observed that it had been launched and had come to rest in the

they rest upon cross and longitudinal timbers: the letters f g refer to the bearing pieces of the fixed ways, and e f to the sliding ways attached to the underside of the caisson. The surfaces of the former of these were cut to an angle, as shown, that of the corresponding slide being made to fit, in order to insure a perfectly true motion of the caisson in the process of launching. Besides this, timbers were bolted to the inside of the two outer ways, which projected above the sliding surface, in order to check any swerving tendency. To insure a means of casting loose the caisson from every point at the same moment, a check cam, shown in the detail, was fixed into each of the ways near the upper end. The cam at the point where it took the bearing of the sliding way was provided with a projection which held it fast against the timber, and it was kept immovable by means of a lever secured by ropes at its extremity.

water.

to leave it as the foundation for the immense towers of the bridge that is to be constructed. This is effected by maintaining and constantly changing an atmosphere, and at the same time excluding the water from each of the compartments of the caisson; thus furnishing means for carrying on the work of excavation to the best advantage. The means to this end are a supply of air forced by steam driven pumps through pipes and hose into the caisson chambers, and a sufficiency of weight on the upper surface of the caisson to counteract the buoyancy alike of timber and air, and maintain the caisson at all times firmly on the bed of the excavation. This weight is provided by commencing at once the erection of the towers. For this purpose the entire surface of the caisson is covered with blocks of heavy stone, the interstices of which are filled with the best cement. As the caisson sinks, other tiers of stone will be added, and when it rests upon its final bed the towers will be carried up their full height.

COMPOUND ENGINES.

IN that Tegn experimenting upon the expansion

year 1776, when Jonathan Hornblower The caisson inclosure extends some 250ft. along of steam in two cylinders successively, there were the river, from thence back about 300ft. The caisson probably no engines in use supplied with steam at itself has a frontage on the river of 168ft., and a a much higher pressure than two or three pounds per depth of 102ft., the basin in which it is being sunk square inch above the atmosphere. Viewed by the extending a few feet more in each direction. The light of our present knowledge, the employment of caisson is, in effect, a box made of heavy timbers, the double-cylinder system under such circumstances 16ft. in depth, and divided by like heavy timbers appears little better than an absurdity, and it is not into six compartments. This great compartmented to be wondered that, after some years of trial, it box, without a cover, was turned bottom upwards was found that Hornblower's engines could not and floated over the spot which it now occupies. compete successfully with the single-cylinder enSeveral layers of timber were then securely bolted gines of Watt. To this result, the fact that the over the entire upper surface, increasing its already independent condenser invented by Watt in 1769 immense strength, and sinking the structure until was found to be a necessary adjunct to Hornblower's its sharp edges-protected by heavy iron plates-engine, no doubt, in some measure contributed. rested upon the bottom of the basin."

The problem was, and is, to sink this enormous caisson through mud and earth and boulders 40 or more feet, until a firm ground is reached, there

Thus matters remained until early in the present century, when, almost simultaneously, Richard Trevithick and Arthur Woolf pointed out that, in order that steam should be worked expansively

The facts we have stated are well-known matters of history, and we should not have alluded to them here had it not been that at the present time they possess a special interest. During the past ten years or so the double-cylinder engine has been again revived, and both on sea and land results have been obtained with it which justify the opinion that, in all cases where great regularity of motion or great economy of fuel is desired, it is the class of engine which should be adopted. Of course such a complete reversal of the former decisions on the single versus double-cylinder engine question is not likely to be at once universally accepted, however conclusive the proofs may be to those who analyze them; and there are, accordingly, not wanting those who, either not caring or not being able to investigate matters for themselves, fall back upon the results of Hornblower's and Woolf's days, and, ignoring present data, maintain that there is nothing in" the compound engine. Under these circumstances it appears to us worth while to point out why the results of the rivalry between Watt and Hornblower, and Trevithick and Woolf, cannot be considered to apply at the present day; and at the same time to show why, in our opinion, the compound engine is likely to take a still higher position in the future.

single-cylinder arrangement, and the difficulty of
keeping these parts tight is therefore greatly di-
minished and the friction reduced. This advantage
is one of which we have spoken more fully on for-
mer occasions.

several million units are often useful; and top. duce such with wire in the ordinary way wod both expensive and cumbrous.

Latterly Mr. Hockin has used selenium for purpose. Fine glass tubes with a platinum in blown in at each end and filled with different fre according to the resistance required, have also be largely used; but these latter necessarily give va variable results, owing to polarization and ele lysis; and the former, I believe, are soIDE difficult to construct.

Requiring a high resistance for some experi I made one as follows:-Upon a strip of vale 6in. long by lin. wide, I ruled several paal i with an ordinary HB pencil in such a man to produce a continuous line about 8-16th of su wide, and 4in. long. At the extremities of the I rubbed the pencil plentifully over a space as.. as a six-penny piece, upon which I firmly two binding-screws by means of "nuts" neath, and, gently dusting off all supertinous bago, varnished the whole with several coats shellac varnish.

The above arrangement gave me a resise slightly over two millions B.A. units. It a structed three months ago, and up to the s time the resistance has remained very com have tested it repeatedly with 100, 200, a cells, and have always obtained the sam within very small limits. It is also be steady with prolonged battery contact.

Mr. G. Preece has kindly tested a resistan in the above manner for me, and finds it ve stant, only getting an alteration of about cent. for 5 Fah. I have mounted a vulcani with twenty binding-screws, giving a wide-ra varied resistances by combination or otherwis hope shortly to make some experiments wite view of determining the ratio of its alteration difference of temperature.-Philosophical Mage

BOILER INSPECTION.

with economical results, the initial pressure must be much higher than had hitherto been used. Trevithick applied high-pressure to Watt's ordinary single-cylinder or Cornish engine, while Woolf revived and modified Hornblower's engine, and, by working it with high-pressure steam, obtained We must now point out why the advantages we results far beyond those of the original inventor. have enumerated did not enable the engines of Woolf's first engine was erected at Meux's brewery Woolf to compete successfully with the Cornish in 1806, but it was not until some seven years later, engine, and to do this we must draw attention to a when he took up his residence in Cornwall, that the fact which, although it can scarcely have escaped second competition between single and double- notice, has yet so far as we are aware never been cylinder engines can be said to have fairly com- advanced to account for the double-cylinder being menced. At first the economy obtained by Woolf an unsuccessful rival of the Cornish engine. This astonished the Cornish engineers, but ultimately fact is that the first and great advantage which we they found that high-pressure steam applied to the have mentioned as attending the employment of the single-cylinder engines produced equally good double-cylinder system is possessed in a great deresults, and thus, for the second time, the double-gree by the Cornish engine also. In other words, it cylinder engine was beaten from the field by its follows, from the manner in which the Cornish more simple rival. engine is worked, that but a small proportion of the surface exposed to the fresh steam from the boiler is ever reduced to the temperature due to the vacuum formed in the cylinder by opening the communication with the condenser. Let us consider, for instance, the case of a Cornish cylinder having an 80in. cylinder, 10ft. stroke, working with a cutoff at one-sixth. In such an engine the piston would probably be abont 12in. deep at the edge, and the length of the cylinder between covers would be about 11ft. 44in., thus giving 24in. of clearance at each end. Now, when the point of cut-off is reached, the internal surface exposed to the steam would consist (disregarding steam passages) of the area of the top cylinder cover+ the area of the top of the piston+the surface of the cylinder itself between the piston and cover, or in all about 15,645 square inches. On the down stroke of the piston being accomplished, the equilibrium valve would, of course, be opened and the piston caused to perform its upward stroke by the load at the pump end of the beam, the communication with the condenser not being open until the equilibrium valve had been closed and the piston had reached the top of its stroke. Under these circumstances the only portion of the 15.645 square inches of surface we have mentioned, which is exposed to the cooling effect due to the formation of the vacuum within We have already stated that in the days when the cylinder, is that which projects below the piston Watt and Hornblower were rivals, the pressures of when the latter is standing at the top of the stroke. steam used were so low that the degrees of expan- Thus, in the 15,645 square inches was included the sion requisite to develope the capabilities of the internal surface of the cylinder for a length of 224in., double-cylinder system were unattainable; and we and of this length 8in. will extend below the piston may therefore dismiss this competition as not re- when the latter is at the top of its stroke. But the quiring discussion here. In the competition be- surface corresponding to the length of Sin. is but tween Woolf and Trevithick, however, the circum- 2,0104 square inches, or but little more than onestances were different, and the pressures of steam eighth of that exposed to the steam at full boiler and degrees of expansion used were such as have pressure. Moreover, this surface of 2,0104 square since been adopted in compound engines with highly inches is exposed to the cooling motion due to the It appears from this report that during the satisfactory results. This being the case, and it formation of the vacuum for but a very brief period; year ending June 30, 25 explosions have o being also an undoubted fact that the double-cylin- whereas, in the ordinary double-acting rotative killing 47 persons and wounding 49 others à der was eventually beaten by the Cornish engine, engine, those parts of the cylinder surface which fewer than 12 boilers exploded within the the question is asked by some engineers why, at have been most highly heated are exposed to the two months (killing 12 and injuring 20 the present time, compound engines are daily grow-cooling action during an entire stroke." not one of which was enrolled in the ing in favour. These facts, while they show that the double-ciation. In nine cases the scene of the cata To be able to answer this question, it is neces- cylinder arrangement possesses no such advantage has been visited, and detailed particulars sary to understand clearly what advantages the over the Cornish as it does over the ordinary single- and, as on all previous occasions, investigati double-cylinder possesses over the ordinary single-cylinder rotative engine, and thus explain to a great shown that these explosions have sprung ins cylinder engine. These are really but three in num-extent the result of the Woolf and Trevithick com- simplest causes; e. g., six were due to malo ber, and of these three but one can be said to petition, afford also an important reason for the tion, one to external corrosion, one to directly conduce to economy of fuel, the other two economy of fuel which has attended the employ- corrosion, and one to shortness of water; w relating more to the economical maintenance of the ment of the Cornish engine. It will, in fact, be the four others sufficient particulars have not in engine, and hence affecting the consumption of fuel seen from what we have stated, that in the Cornish received to allow of a positive opinion beingf indirectly. Theoretically, of course, the expansion engine the piston and equilibrium valve serveof the steam in two cylinders successively possesses although less perfectly-much the same purpose as no economical advantage over an equal degree of the second cylinder in the compound system, and expansion carried out in a single cylinder; and that, therefore, a competition between the doublepractically, there is a certain loss involved by the cylinder and Cornish engines was a very different employment of the double-cylinder arrangement, thing to the competition between compound and owing to the loss of pressure in the passages by single-cylinder rotative engines, such as is going on which the two cylinders are placed in communica- at the present day. Moreover, in the competition tion. Any loss due to this cause, however (so long with the Cornish engine, the second and third adof course as proper proportions are used), is far vantages which we have mentioned as attending more than counterbalanced by the fact that, in the the double-cylinder arrangement, went almost for double-cylinder arrangement, the cylinder receiving nothing, and thus the result of the Woolf and the high-pressure steam is never cooled down much Trevithick is altogether fully accounted for. below the temperature of that steam, and the low- We have said that we anticipate the more and pressure cylinder, in fact, forms a kind of heat-trap more extensive adoption of the compound engine, between the high-pressure cylinder and the con- and the reasons for this are, we consider, self-evidenser. This fact, which constitutes the first great dent. As steam of higher and higher pressure is advantage of the double-cylinder arrangement, has used, the action of the second cylinder in preventlong been well known and recognized; but there has ing the cooling of the surfaces exposed to this steam apparently been in many quarters a disinclination becomes of more and more importance; while, as to estimate it so highly as it really deserves. All, higher degrees of expansion are resorted to, the however, who have carefully watched the perform greater equality of driving pressure obtainable by ance of compound engines-and especially engines the double-cylinder arrangement rapidly increases working with high degrees of expansion-must in value. The compound engine certainly does not have become convinced that this advantage is one possess the charm of novelty; but it possesses the of vast importance, and that it is almost to it alone greater charm of having proved by its perform that the high duty obtained from well-constructed ances that it is well entitled to the esteem of users double-cylinder engines is due. of steam-power.-Engineer.

The second advantage of the compound engine, and the one perhaps that is most generally attributed to it, consists in the regularity of motion which can be obtained with it, and the facilities it affords ON A SIMPLE METHOD OF CONSTRUCTING for vastly reducing the sudden strain thrown on the HIGH ELECTRICAL RESISTANCE. moving parts at the commencement of each stroke. Of this advantage we need not speak further at present. The third advantage lies in the fact that with the compound engine the effective differences A of steam pressure tending to cause leakage past ling the pistons and valves are much less than in the size.

T

BY SAMUEL E. PHILLIPS, Jun.

present resistance-coils are mostly made with German-silver wire; and a set of coils equal10,000 B.A. units forms a box of convenient But in electrical research resistances of

Fletcher, the chief engineer of the Man E have before us the latest report of M chester Steam Users' Association, presented at the meeting of the committee, held on July 26th. From this document we find that during the past two months 485 visits of inspection were made, au 1.106 boilers examined. In these no fewer tha 207 defects were discovered, 14 of them bein dangerous; and there can be little doubt that least a moiety of these fourteen dangerous defr were prevented from resulting in explosions by: timely inspection of the officers of this associat

To show how necessary it is that some d periodical inspection of boilers should be er we will instance an explosion which took pie Tuesday, June 21st, at an iron works, ana from the failure of a plain cylindrical exte fired boiler, at a longitudinal seam of riv the fire, at which repeated repairs had b cuted. The facts with regard to this expl of interest, and demand more than a pass It appears that a competent independent had examined the boiler in 1864, at the the owners, and condemned it as unei pressure at which it was worked. In 18 inspector examined it again with the sam but the boiler was worked on at the pressure nevertheless. In 1870 it burst, kills? people.

At the inquest, three engineers were found ▼ after having made a careful examination, could account for the explosion, and thought the bi was perfectly safe at the pressure at which t owner worked it, and that he exercised a discretion in so doing," notwithstanding that boiler had been burst in consequence, and that L were then engaged in investigating the deaths two persons killed thereby. The jury returnal verdict of "Accidental Death;" but, in spite of is evidence given by the three engineers just refers to, stated that they considered the owner had en mitted an error in judgment in working the br at the pressure he did after he had been advisedi the independent inspector already referred to. reduce it. To those who are endeavouring to soi the problem of making efficient periodical bo inspection general throughout the country, such a explosion and such evidence are pregnant w

instruction.

Another explosion, of rather peculiar nature happened at about half-past five on the afternos

Friday, May 27th, killing two persons. It was used by the boiler of an auxiliary or donkey gine employed on board a passenger steamer, low decks. This boiler was not examined by an icer of this association, but it is reported that e explosion arose from the rending of the internal sing of the fire-box from overheating of the plates sequent on shortness of water.

At the inquest it was stated that this shortness water and consequent overheating arose through e blow-out tap being left open through oversight, d that against such oversights science could prode no remedy, so that the explosion was accintal.

A

come, and let P represent the force required E to cause the piece just to Not having received a detailed report on this move round the axle tastrophe, Mr. Fletcher offers the following reAA L, it is required to arks thereon with some diffidence; but it appears find the magnitude of P mportant to point out that before the view can be (whose direction is supposed to be given) and the ccepted that modern science is powerless to pre-magnitude and direction of the resultant of P and ent such explosions, it must be proved that all its Q. Produce C B and E D to meet at H. Let H L be opliances have been exhausted. Was such the the direction of the resultant of P and Q. Now, since, ise in the present instance? As blow-out taps by the nature of the question, P is on the point of ave been found occasionally to be left open through causing motion, the resultant of P and Q must make versight, they are sometimes equipped on board at the point L, where it cuts the circle, an angle equal ip with a guard, arranged so as to prevent the top with the radius L K, for L is clearly the point of ey being withdrawn unless the plug be turned so contact between the axle and its bearing, and L K is to close the tap. Again, to give warning of the direction of the perpendicular at the point of conortness of water, from whatever cause that may tact, and therefore in accordance with the principle already laid down, viz., when a body just commences ise, fusible plugs adapted for marine boilers may to slide on another body the resultant of the forces employed,-not those attached to the crown of ie furnace which for many reasons are objection-acting on it must make with the normal to the surface ble on board ship, but those fixed at the end of a friction, the angle H L K must be equal to . (point or line) of contact an angle equal to the angle of ipe carried up from the boiler, as already explained the association's printed reports for January, 865, and November, 1869. Before therefore it can e concluded that such explosions are unavoidable, must be asked whether these two simple applinces, in such common use elsewhere, have received a fair trial. If not, it cannot be considered that such disasters are accidental, but that there is every reason to conclude that they might be prewented by efficient boiler mountings.

These instances are surely sufficient to convince any one of the need there is for some systematic Inspection of boilers, especially when it is shown so clearly what a large amount of good in the way of prevention has been achieved by the Manchester Steam Users' Association.

IMPROVED PORTABLE STEAM ENGINE.

(Illustrated on page 469.)

E learn from a pamphlet issued by the makers,

Let K L = r, and from K let fall a perpendicular
K N on HL, then K N = r sin 4, so that in order to
draw H L we must describe a circle round K with a
radius equal to r sin o, and draw from H a line H L
touching it in N. To find now the magnitude of P,
from the point N on H L draw the perpendiculars N Q
and N P ; then, since the moments of two forces round
any point on their resultant are equal and opposite, we
must have
NQ

=

PX NP Q× NQ, or P Q × NP
Having now the value of P, we have for the magnitude
of R, the resultant of P and Q, by the well known
formula

R = √P2 + Q2 + 2PQ cos. CHE
When P and Q are parallel, R is parallel to them
both, and equal to their sum or difference, according
as they act in the same or opposite direction. In this
case Q N, K N, and N P, are in one right line. The
above applies to all cases of the LEVER and the WHEEL
AND AXLE when friction is taken into account. Thus
if a force P be applied at the end of one arm p of a

WE meting at

Mass., United States, that "an attempt is made in this engine to superheat the steam, mildly, yet effectually, and to secure all the advantages of a steam jacket around the cylinder, with the utmost simplicity and increased economy. The principle means employed are:

"1st. Surrounding the cylinder by the waste gases, the products of combustion, on their passage from the smoke-box to the smoke-pipe; securing thus a smoke-jacket' instead of the well-known 'steam-jacket.'

"2nd. Placing the feed-water heater in the smoke-box, below the cylinder, so as to reduce the temperature of the gases to a safe point before they reach the cylinder.

3rd. Conveying the steam from the governorvalve, which is located within the steam dome, through the steam space, the whole length of the boiler to the flue-sheet, and thence by a curved pipe through the smoke-box to the steam-chest; by which means it is safely yet thoroughly dried and slightly superheated."

These objects, it is asserted, are attained in this engine, which has 7in. diameter of cylinder and 10in. stroke, weighs, exclusive of running gear, 4,500 pounds, and is capable of exerting permanently and economically 15-horse-power. Indeed, it is said to have been run for several weeks to drive the machine-shop of its builders, which, with other work driven by the same water-wheel, is known to require from 25 to 33-horse-power; a very creditable performance for an engine usually rated at 10-horse-power. The boiler is lagged with wood, and cased in sheet iron, with brass bands. practice, common in England, has not been generally adopted, hitherto, by American engineers. It adds something to the bulk of the boiler, a little to the weight, and considerably to the cost; but the makers claim that it adds in an equal or greater degree to its efficiency.

FRICTION.-IX.

This

BY C. DRAPER, A.B., L.C.E. (Continued from page 250.) FRICTION OF AN AXLE.-So far we have had no question involving the friction of surfaces other than plane; but we shall now investigate the condition of equilibrium of a body supported by and capable of turning round an axle.

It is quite clear that since an axle turns in its bearings the diameter of the latter must be slightly greater than that of the former, so that they are in reality only

|

FIC.22

7ft. 8in. from B, and 561b. at the required distance a

from B. The resultant of these three forces must act

at a point distant r sin from the centre of the axis, therefore of 2,3521b. must be equal and opposite to the sum of the moments of 602 and 56 round this point. Now since r = 1 and sin = 1-6th nearly, we have r sin fin., therefore 2ft., less fin. or 1ft. 11 in., is the distance of 2,352 from the resultant, similarly 7ft. 8 in. and x ft. 0 in. are the distances of 602 and 56 from the same point. This is further shown in the

and on the side of the axis next c. The moment

axle, Fig. 20 is reduced to Fig. 21, the same letters in- acting on it will be the resultant of the weight of the

dicating corresponding points in each.

Here N P = p r sin, and NQ = q r sin .
g+r sin
Pr sin P

shaft, together with whatever wheels, &c., may be supported on the shaft, the forces to be overcome, and the forces which drive the shaft, which may be transmitted through a band, connecting rod, &c. In the latter case the magnitude and the direction of the resultant force will be continually changing, so that we can only arrive at an average result.

.. P = Q x In fact, the forces P and Q, instead of balancing round the centre of the axle, which they would if there were no friction, balance round a point N, nearer the pre-acting on the shaft, or the pressure of the bearing dominating force P by the distance r sin p.

therefore P Q
From this formula we see that the smaller r is, or
the less the diameter of the axle, the less will be the
effort required to overcome the friction.

Given the

In Fig. 20, let R be the resultant of all the forces against the axle; then the shaft will just commence to revolve when R makes an angle with the radius (as was shown above); the friction overcome is then R cos

tan = R sino, since R cos is the normal pressure;

this friction is overcome for a distance 2 r during each revolution, therefore the work lost during one revolution is 2 Rr sin 4. In most cases sin is practically equal to tan p = μ.

EXAMPLE 18.-The weight of the cranked shaft and fly-wheel of a steam engine is 1 tons; the diameter of the shaft is 4in.; if the engine makes 30 revolutions per minute, determine approximately the units of work expended in turning the fly-wheel for one minute, if μ= 05.

pressure, we have for the work lost :-
Taking 1 tons or 2,800 pounds as the resultant
30 x 22 x

EXAMPLE 17.-Fig. 22 is an isometrical sketch of a building is going on, in order to check the weights of rough weighing machine, frequently erected where the materials supplied. It consists of a scale pan A hung from the end of the short arm of a long timber lever, whose axis or fulcrum is at B. 4 × 2,800 4,400 units of work per minute dimensions and weights of the beam &c., and the 7 x 12 x 20 EXAMPLE 19.-A grindstone, whose diameter is 4ft., coefficient of friction, it is required to know at what distance from B a weight W of 561b. must be hung in turns on an axle 2in. in diameter; the belt by which order that the beam and weight may be just counter-it is driven slips when making 15 turns per minute; find the number of turns it will make before it stops balanced by one ton placed in the scale pan. The beam is of oak, 20ft. long, 1ft. deep, and 6in. if the coefficient of friction is 3-40ths. wide, weighing 55lb. to the cubic foot; the point of suspension of the scale pan is 2ft. from the axis, which is 3in. in diameter, and whose coefficient of friction is 1-5th. By an experiment, the beam with the hook and axis attached, balances at a point 7ft. 3in. distant from the axis; the centre of gravity is therefore situate at this point. The beam weighs 20 x x 55 = 550lb., the hook weighs 181b., and the axis 341b. We have therefore the following forces acting on the lever, 2,240 + weight of scale pan 2,3521b. at C, 550 + 18+ 84 = 6021b. at D, distant

The easiest key is one flat; and four sharps is as easy, as three, because the D sharp is made by the thumb of the left hand, and by keeping the thumb down, all the other fingering remains the same throughout.

THE FLUTE.

PROPELLER.

[163] SIR,-In your impression of the 8th inst., I find a letter on flute fingering, signed "T. S. G." As that letter is calculated to do harm to the " uninitiated," I trust you will grant me space for the publication of this one. The tuning slide of a flute is merely in tended to flatten the pitch a little, not to put the instrument in another key. To tune the D natural down to D flat it would require the slide to be pulled out about lin., and that would (for the time) utterly destroy the proportionate division of the instrument. It would appear to me that "T. S. G." thinks that it does not matter much where the holes and keys are placed.

The difficulties are the same whether playing in extreme flat keys or extreme sharp ones; and those difficulties cannot be surmounted by any clumsy expedient, but by the careful, patient, slow, and diligent practice of scales and studies in all the keys. The eighteen studies of Berbiguier and Dressler's scales are the best things I know of.

There is no royal road to flute-playing any more than to any other art or science, and it is only by the practice of such things as I have named that perplexed fingers" will find relief. HENRY CHAPMAN.

HANDWRITING.

[164] SIR,-May I ask an opinion on the almost illegible style of writing now so generally practised? It appears that the farther it is possible to depart from the true, correct, and beautiful form of the letters the more stylish the writing is, according to prevailing opinion. How has it come to pass, that such deformity in writing is tolerated, and even considered excellent, whilst in any other art such a departure from truth would be considered a mark of ignorance and vulgarity? W. S. A.

CURIOUS SENTENCE.

[165] SIR,-The curious formation of the sentence given on p. 423, letter 92, is better seen when the text is arranged in the following manner :

SATOR
AREPO
TERET
OPE RA
ROTA S

But are not the makers of such puzzles guilty of loss of time? I can quote, as similar examples, the Pugna Porcorum per potatorem porcium poëtam præclarem, a poem of 290 verses, all the words of which begin with the letter p; and a little Portuguese work, in five chapters, the 1st without a, the 2nd without e, the 3rd without i, the 4th without o, &c. This is so much more difficult that in that language the definite articles are o and a. But too much space taken already-I end. BIBLIOPHILUS.

ON THE PIANOFORTE.-FROM "W. T." [166] SIR,-I beg permission to answer several correspondent's questions-some addressed generally to your readers, others at the special request of the

"Harmonious Blacksmith."

"Piano-felts-and what I felt on reading the question."-Mr. Tim Bobbin says, No. 3855, that he should

in
like to see hammer and damper felts "made "
England. May I tell him that he can see any quantity
thereof that he is willing to purchase. But although
this is the strictly grammatical interpretation of his
words, I am willing to assume that he wishes to see, not
the felt, but the process of making it.

Having "presumed to assume that he means this,
I further presume, and I hope he will forgive my pre-
sumption, to give him a bit of advice, founded on my
experience of "London society." It is, that when you
solicit a favour, it is best to make a respectable ap-
pearance. Let "Tim Bobbin" alter his costume from
the traditional shirt sleeves and porter pot, in which
and
he is usually represented, without a cravat -
put on a clean shirt, unexceptionable tie, a gentle-
manly suit of black broadcloth-i.e., not the 60s. suit of
the advertising tailors, who don't know how to cut a coat,
unless it be for fast men, betting men, and other men than
gentlemen, but do know, only too well, how to make
the money of their customers, cut out his pockets into
theirs-also a gentlemanly "chimney pot," without
abnormal brim or crown. If the latter is adorned with
a broad crape band, all the better, for this imparts an
additional air of respectability-people who don't rea-
son closely, inferring that your band would not have
been so broad if you had not received a considerable
legacy; and, above all, don't forget unexceptionable
boots and well-fitting kid gloves.

Having prepared himself thus far, his next step
should be to visit the purlieus of Soho and Leicester-
square, where, by the exercise of a little tact and dis-
crimination, he will be able to select, for a small con-
sideration, and in addition, a suit of the externals I
have recommended him to assume, a distinguished
foreigner," for whose especial behoof, he is anxious,
during his flying visit to England, to see the process of
felt making as one of the "sights of London."

66

Both being thus properly "togged" (I trust Mr.
Editor, your familiarity with the tongue of Cicero will
enable you to perceive this word is a legitimate descen-
dant of the classic Roman toga), Mr. "Tim Bobbin"
being "disguised," not as usual, in liquor, but in un-
usual toggery-and having practised the proper position
of his H's-may safely venture to No. 14, Hanover-
street, Long Acre, the offices of the Wandle Patent
Felt Company, Limited, and after duly presenting his
own, and his "distinguished" friend's cards, let him
ask to see the respected manager of the said company,
whom he will find to be one of the most gentlemanly
men it has ever been my good fortune to be acquainted
with-no small consolation, considering the unavoid-
able rubbing of shoulders one is often obliged to endure
with those to whom inclination would prefer giving a
wide berth. Let Mr. "Tim Bobbin" then prefer his
very modest request, and I have no doubt he will receive
all the attention he can possibly expect.
If Mr. "Tim Bobbin" pondered the matter for a
twelvemonth, could he devise a better plan for eliciting
a trade secret? Stay-I must very earnestly beg his
pardon. Commercial considerations cannot, of course,
influence so highly respected an individual. No, by no
means. It is but the landable desire to add to his stock
of knowledge. Go on then, Mr. "Tim Bobbin," and

BRINSMEAD'S HISTORY OF THE PIANOFORTE,
AND A "LEETLE" MORE.-LETTER II.
[167] SIR,-The advent of the celebrated twelve
apostles in 1760 is duly recorded. The author seems to
think their mission was to convert the British barbarians
of the period from the love of their old not very sweet-
heart the harpsichord to that of the piano. I have a

strong suspicion that they had no more consciousness
of this mission than the very many of their countrymen
who emigrate to the United States of America have of
their mission to civilize-or, rather to improve off the
Like astute
face of the earth-the Red Indians.
Scotchmen, at a later time in Britain's history, they
followed the example of the Phoenicians, and came to
England for "tin"-or at least for more lucrative em-
ployment than their own country afforded them. These
apostles "with a mission" seem to have been quite
content to subside into obscurity; unless, indeed, some
of them afterwards cropped up under the names of
Zumpe, Pohlman, Buntebart, and Co., several of whose
productions yet exist; for instance, the Joannes Zumpe,
fecit A.D. 1776, which was in the possession of Mr.
Ramsay, of Bury, in 1802. According to Capel Loft,
Sir George Smart possessed a square piano, also made
by Zumpe, in which some of the keys were divided as
they were in some spinets and harpsichords, to produce
what are incorrectly termed quarter tones, for amend-
ing the unavoidably imperfect intonation of instru-
ments which are limited to twelve intervals. Although
the Zumpe, dated 1776, is the earliest square piano
certainly made in England which I remember to have
read of, it is probably far from the first made here; for
squares were not uncommon in Germany at least nine-
teen years before; and if Plenius could copy a hammer
harpsichord, surely sufficient ability must have existed
to copy a square piano, although I am willing to admit
it is, from its excessively narrow scale, by far the most
difficult form of the instrument to "finish" satisfae-
torily.

That square pianos were pretty well known on the Continent long before the advent of the apostles-I mean the high Dutch ones-is conclusively proved by the fact that Old Bach played on several "forte pianos" made by Silberman, at the palace at Potsdam, in 1747. As an engraving of one exists-which is copied by Rimbault (page 119)-it has rather thin round legs, but is not half so ugly as some made long after in England; but then we must allow for the public taste in the times of the Georges. From it we may pretty confidently assume that their legs were all "quite on the square."

That harpsichords with hammers added to jacks were not very uncommon on the Continent I have already stated. They seem to have been in pretty extensive use during the latter portion of the first half of the eighteenth century; for example, the Reverend Poet Mason, the inventor of the celestinettes, writes to his friend and fellow poet Gray, in 1765, "I have bought, at Hamburg, such a pianoforte, and so cheap. It is a harpsichord too (sic) of two unisons, and the jacks serve as mutes (query as dampers) when the pianoforte stop (it was the age of stops to stringed instruments) is played, by the cleverest mechanism imaginable." Perhaps, after more than a century's experience, we may be excused for doubting the extraordinary "cleverness" of this unknown mechanism, for nothing fit to be termed clever has come down to us; but I dare say that

like the calculating boy, George Bidder, Esq.-it was thought very clever in its day. It is rather amusing to read on, for with the self-abnegation of a modern Englishman, who has bought a new and better horse and is tired of his old one, he proceeds to ask his friend It is and fellow-poet "won't you buy my Kirkman?" very remarkable how willing poets and even parsons (both of whom are well known to abhor that filthy lucre which is very incorrectly-said to be the root of all evil) are, benevolently to "sell" at once their left

off chattels and their friends.

Mr. Brinsmead goes on to say that the piano became a very popular concert instrument, basing this statement on certain announcements yet extant of its intended use, such as Michael Arne's presiding at the pianoforte (query the harpsichord) in Dublin Theatre, and its employment for accompanying the voice of