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The structure was put together with its longer side parallel to the river bank, eters d and about 100ft. distant instance from it, and the ways upon

and the which it rested were seven

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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.

ceived in number, and each about 180ft. in length. These These ropes being cast off simultaneously, the rd pressways were laid in such a manner that their cams were thrown over, and the caisson was free apper faces were curved to a radius of about to move equally throughout its length. The posijack 5812ft., and at a slope which made the chord of low has this are form an angle of about 5°, the curved des ups sine of the arc being some 13in., and the upper hollo ends of the ways 15-6ft. higher than the lower into the ends. By this means an accelerated motion was botte given to the caisson in the latter part of its umb-transit; the increased velocity it thus obtained as gr enabled it to overcome the great resistance it encountered from the water when it struck the and sec river broadside on. The details show the form iamete given to these ways, and it will be observed that -condas they rest upon cross and longitudinal timbers: water. r-works the letters f g refer to the bearing pieces of the havi fixed ways, and e f to the sliding ways attached the river, from thence back about 300ft. The caisson probably no engines in use supplied with steam at

pipes

to the underside of the caisson. The surfaces of the former of these were cut to an angle, as as shown, that of the corresponding slide being made ible to fit, in order to insure a perfectly true motion of the caisson in the process of launching. Besides this, timbers hl 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.

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
it had been launched and had come to rest in the
The caisson inclosure extends some 250ft. along
itself has a frontage on the river of 168ft., and a
depth of 102ft., the basin in which it is being sunk
extending a few feet more in each direction. The
caisson is, in effect, a box made of heavy timbers,
16ft. in depth, and divided by like heavy timbers
into six compartments. This great compartmented
box, without a cover, was turned bottom upwards
and floated over the spot which it now occupies.
Several layers of timber were then securely bolted
over the entire upper surface, increasing its already
immense strength, and sinking the structure until
its sharp edges-protected by heavy iron plates-
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

N the year 1776, when Jonathan Hornblower of steam in two cylinders successively, there were a much higher pressure than two or three pounds per square inch above the atmosphere. Viewed by the light of our present knowledge, the employment of the double-cylinder system under such circumstances appears little better than an absurdity, and it is not to be wondered that, after some years of trial, it was found that Hornblower's engines could not compete successfully with the single-cylinder engines of Watt. To this result, the fact that the independent condenser invented by Watt in 1769 was found to be a necessary adjunct to Hornblower's engine, no doubt, in some measure contributed. 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

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.

with economical results, the initial pressure must
be much higher than had hitherto been used.
Trevithick applied high-pressure to Watt's ordi-
nary 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 de-
results, 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 com-
munication with the condenser. Let us consider,
for instance, the case of a Cornish cylinder having
an 80in. cylinder, 10ft. stroke, working with a cut-
off at one-sixth. In such an engine the piston
would probably be about 12in. deep at the edge,
and the length of the cylinder between covers would
be about 11ft. 4in., 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 per-
form its upward stroke by the load at the pump
end of the beam, the communication with the con-
denser 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
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- 2,010 square inches, or but little more than one-
stances 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
satisfactory results. This being the case, and it formation of the vacuum for but a very brief period;
being also an undoubted fact that the double-cylin- whereas, in the ordinary double-acting rotative
der was eventually beaten by the Cornish engine, engine, those parts of the cylinder surface which
the question is asked by some engineers why, at have been most highly heated are exposed to the
the present time, compound engines are daily grow-cooling action during an entire stroke.
ing in favour.

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.

we have mentioned, which is exposed to the cooling

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

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

Requiring a high resistance for some experi I made one as follows:-Upon a strip of val 6in. long by lin. wide, I ruled several pencil & with an ordinary HB pencil in such a mane to produce a continuous line about 3-16th of s wide, and 4in. long. At the extremities of th I rubbed the pencil plentifully over a space is) as a six-penny piece, upon which I firmly s two binding-screws by means of "nuts" neath, and, gently dusting off all superfluous bago, varnished the whole with several coatse shellac varnish.

The above arrangement gave me a resis slightly over two millions B.A. units. It structed three months ago, and ap to the time the resistance has remained very con have tested it repeatedly with 100, 200, cells, and have always obtained the san 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 vulcanit with twenty binding-screws, giving a wide-re varied resistances by combination or otherwis hope shortly to make some experiments with view of determining the ratio of its alteration difference of temperature.-Philosophical Mage

BOILER INSPECTION.

Fletcher, the chief engineer of the ManE have before us the latest report of Mr 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, and 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 s least a moiety of these fourteen dangerous defe were prevented from resulting in explosions by timely inspection of the officers of this associati

It appears from this report that during the year ending June 30, 25 explosions have oc killing 47 persons and wounding 49 others fewer than 12 boilers exploded within th two months (killing 12 and injuring 20 not one of which was enrolled in the These facts, while they show that the double- ciation. In nine cases the scene of the cat 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, investigative e double-cylinder possesses over the ordinary single- cylinder rotative engine, and thus explain to a great shown that these explosions have sprung free 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 intes directly conduce to economy of fuel, the other two economy of fuel which has attended the employ-corrosion, and one to shortness of water; wh 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 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 being fame indirectly. Theoretically, of course, the expansion engine the piston and equilibrium valve serve- To show how necessary it is that some e of the steam in two cylinders successively possesses although less perfectly-much the same purpose as periodical inspection of boilers should be ef no economical advantage over an equal degree of the second cylinder in the compound system, and we will instance an explosion which took pla expansion carried out in a single cylinder; and that, therefore, a competition between the double- Tuesday, June 21st, at an iron works, and w practically, there is a certain loss involved by the cylinder and Cornish engines was a very different from the failure of a plain cylindrical exter employment of the double-cylinder arrangement, thing to the competition between compound and fired boiler, at a longitudinal seam of rive owing to the loss of pressure in the passages by single-cylinder rotative engines, such as is going on the fire, at which repeated repairs had be which the two cylinders are placed in communica- at the present day. Moreover, in the competition cuted. The facts with regard to this expl tion. Any loss due to this cause, however (so long with the Cornish engine, the second and third ad- of interest, and demand more than a pass of course as proper proportions are used), is far vantages which we have mentioned as attending It appears that a competent independenti more than counterbalanced by the fact that, in the the double-cylinder arrangement, went almost for had examined the boiler in 1864, at the double-cylinder arrangement, the cylinder receiving nothing, and thus the result of the Woolf and the owners, and condemned it as unst the high-pressure steam is never cooled down much Trevithick is altogether fully accounted for. pressure at which it was worked. In 186 below the temperature of that steam, and the low- We have said that we anticipate the more and inspector examined it again with the sam pressure cylinder, in fact, forms a kind of heat-trap more extensive adoption of the compound engine, but the boiler was worked on at the p between the high-pressure cylinder and the con- and the reasons for this are, we consider, self-evi- pressure nevertheless. In 1870 it burst, hill denser. This fact, which constitutes the first great dent. As steam of higher and higher pressure is people. 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.

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

At the inquest, three engineers were found th after having made a careful examination, could account for the explosion, and thought the b was perfectly safe at the pressure at which owner worked it, and that "he exercised & F discretion in so doing," notwithstanding that boiler had been burst in consequence, and that th were then engaged in investigating the deaths4 two persons killed thereby. The jury returned verdict of "Accidental Death;" but, in spite of th evidence given by the three engineers just referre to, stated that they considered the owner had co mitted an error in judgment in working the bo at the pressure he did after he had been advised b the independent inspector already referred to, reduce it. To those who are endeavouring to so the problem of making efficient periodical ho inspection general throughout the country, such as explosion and such evidence are pregnant with instruction.

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

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Friday, May 27th, killing two persons. It was insed by the boiler of an auxiliary or donkey gine employed on board a passenger steamer, low decks. This boiler was not examined by an Beer 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 nsequent 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 pro-
de no remedy, so that the explosion was acci-
ntal.

in contact in a single point, or, to speak more correctly,
in a single line parallel to the axis, whose length is
equal to that of the bearing.

FIG.20

H

D

In Fig. 20, let A A L represent the transverse section of an axle, let B C and DE represent two forces, Q and P, acting on the piece supported by the axle. To fix the ideas, let Q be the resultant of the weight of the piece P and the forces to be overcome, 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 HL be ppliances 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 by 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 conhortness of water, from whatever cause that may tact, and therefore in accordance with the principle ise, fusible plugs adapted for marine boilers may already laid down, viz., when a body just commences to slide on another body the resultant of the forces employed,-not those attached to the crown of e 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, at must be asked whether these two simple applirances, 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 prevented 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.)

Let K L =r, and from K let fall a perpendicular
K N on H L, then K N = r sin p, so that in order to
draw H L we must describe a circle round K with a
radius equal to r sin p, 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
NP

=

PX NP Q× NQ, or P = Q ×
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+ 2 P Q 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 QN, 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

WE learn from a pamphlet issued by the makers, if a force P be applied at the end of one arm p of a

Messrs. J. C. Hoadley & Co., of Lawrence 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.'

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"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 governorartial valve, which is located within the steam dome, ive op through the steam space, the whole length of the

straight lever to overcome a parallel force Q acting at
the end of the other arm q, and if r be the radius of the

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Now had there beer no friction, we should have had simply::

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Therefore, owing to the friction, the 561b. weight must be placed 2ft. 1fin. nearer to the axis than if there

were none.

We shall now consider the question of how much work is lost during each revolution of a shaft in its bearings. In this case, the resultant of the forces

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

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dicating corresponding points in each.
Here N P = p r sin, and NQ
9 + r sin
P - r sin o

.. P = Q ×

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

In fact, the forces P and Q, instead of balancing round resultant force will be continually changing, so that

it is ta boiler to the flue-sheet, and thence by a curved pipe the centre of the axle, which they would if there were
ilers through the smoke-box to the steam-chest; by
iron slightly superheated."

we can only arrive at an average result.

on she which means it is safely yet thoroughly dried and no friction, balance round a point N, nearer the pre-acting on the shaft, or the pressure of the bearing

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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

These objects, it is asserted, are attained in this small fractions, especially when a lubricant is used,
As the coefficients of friction of axles are generally
engine, which has 7in. diameter of cylinder and will be a small angle, varying in fact from about 32 to
10in. stroke, weighs, exclusive of running gear, 5; consequently sin will be very nearly equal to tan tan = R sin o, since R cos is the normal pressure;
or u, so that in the above formula, we may, without this friction is overcome for a distance 2 ar during

ral to the 4,500 pounds, and is capable of exerting permanently

at indepen

said to have been run for several weeks to drive

re than sp and economically 15-horse-power. Indeed, it is appreciable error, substitute,
1864, at the machine-shop of its builders, which, with other
ed it as 12 Work driven by the same water-wheel, is known to
rked require from 25 to 33-horse-power; a very credit-

therefore P =

Q

μ

for sin,

q +με pur.

each revolution, therefore the work lost during one revolution is 2 Rr sin . In most cases sin is practically equal to tan p = μ.

EXAMPLE 18.-The weight of the cranked shaft From this formula we see that the smaller r is, or and fly-wheel of a steam engine is 13 tons; the

with the able performance for an engine usually rated at the less the diameter of the axle, the less will be the diameter of the shaft is 4in.; if the engine makes 30 on at 10-horse-power. The boiler is lagged with wood. effort required to overcome the friction. $70 it bars and cased in sheet iron, with brass bands.

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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.
dimensions and weights of the beam &c., and the
coefficient of friction, it is required to know at what
distance from B a weight W of 561b. must be hung in
order that the beam and weight may be just counter-
balanced by one ton placed in the scale pan.

Given the

The beam is of oak, 20ft. long, lft. deep, and 6in.
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 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 +34 6021b. at D, distant

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4,400 units of work per minute 7 x 12 x 20 EXAMPLE 19.-A grindstone, whose diameter is 4ft., turns on an axle 2in. in diameter; the belt by which it is driven slips when making 15 turns per minute; find the number of turns it will make before it stops if the coefficient of friction is 3-40ths.

The work accumulated in a rotating body is equal to the product of its moment of inertia into half the square of its angular velocity. Let R be the radius of the stone, M its mass, and its angular velocity at the instant the band slips; then M

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IMPROVED PORTABLE STEAM ENGINE. (Described on page 467).

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 A REPO TERET OPERA ROT A 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

like to see hammer and damper felts "made" in 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 presumption, 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 appearance. Let "Tim Bobbin "alter his costume from the traditional shirt sleeves and porter pot, in which he is usually represented, without a cravat- and put on a clean shirt, unexceptionable tie, a gentlemanly 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 additional air of respectability people who don't reaa broad crape band, all the better, for this imparts an 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 Leicestersquare, where, by the exercise of a little tact and discrimination, he will be able to select, for a small consideration, 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."

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 descendant of the classic Roman toga), Mr. "Tim Bobbin" being "disguised," not as usual, in liquor, but in unusual toggery-and having practised the proper position of his H's-may safely venture to No. 14, Hanoverstreet, 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 unavoidable 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

prosper.

W. T., Pianoforte Tuner and Repairer.

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 face of the earth-the Red Indians. Like astute 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 employment 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 amending the unavoidably imperfect intonation of instruments which are limited to twelve intervals. Although certainly made in England which I remember to have the Zumpe, dated 1776, is the earliest square piano read of, it is probably far from the first made here; for squares were not uncommon in Germany at least nineteen 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" satisfaetorily.

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 and fellow-poet "won't you buy my Kirkman?" It is 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 off chattels and their friends.

BRINSMEAD'S HISTORY OF THE PIANOFORTE, all evil) are, benevolently to "sell" at once their left

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 sweetheart the harpsichord to that of the piano. I have a

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

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