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NQUIRIES: ANSWER TO INQUIRY. pendicular height of the parallelo- substitute in the making of beer. gram, according to the construc- If, however, in addition to the in. tion, is the radius added to the tan- formation above requested, any of gent of 300=1.5773503, and the area your Correspondents can give fur, is 3.1547006, instead of 3.1415926, ther information as to the advan, the area of the circle. The segment tages and disadvantages of the use cut off by the construction will be of it, or refer to works where it may found only 1090 28', instead of 1100 be obtained, I shall be additionally 23', neglecting seconds.

obliged.
I am, Sir, yours, &c.

I am, Sir,
N.H.
Your constant reader,

J. S.M.

INQUIRIES.

ANSWER TO INQUIRY. No. 120.-EFFECT OF DEPTH ON

THE QUALITY OF WATER.
SIR,-Can any of your Corre. No:

No. 97.-QUESTIONS ON GUNNERT. spondents inform me, through the

[Second Answer.] medium of your Magazine, whether : SIR, The only certain way of comwater is softer at one hundred yards puting the charge of powder for a deep than it is at eight or ten yards fowling-piece is by weight, and not deep? I understand this is the case by the space it occupies in the barrel; at Leeds; and that, for the use of and also the quality of the barrel steam-engines, they shut the top should be expressed, for a difference water off, and bore from eighty to in expansion makes a difference in one hundred yards, in preference to the quantity required for a charge: going to the river. I wish to know for instance, the Damascus and comwhether this applies generally, or mon barrels, on account of their less only to particular situations, as Leeds, expansibility than the twisted barrels, for instance,

shoot equally strong with the latter Also, what is best, for steam when the charge of powder is reboilers, to soften water?

duced four grains; for it must be .:. - I am, Sir,

obvious to every one, that the shot

could not be dislodged with equal • Your most obedient seryant, force when the sides of the barrel

G. C. E. yield to the sudden expansion of the Loughborough..

exploded powder ; and here I may add, that the shot travels with a much greater velocity than the rarefaction

that moved it, which shows that the No. 121...COMPARATIVE STRENGTH shot receives no accumulation of

OF MALT AND SUGAR. . force by the quantity of powder which Sir...Will you allow me, through is put into the barrel, more than what the medium of your pages, to make is fired in the first instant, as the an inquiry relative to a subject shot is propelled by the first rush which interests every man who brews - of the air on the combustion of the his own beer-I mean the compara- powder. tive strength of Malt and Sugar. The accompanying scale' will be The basis of all fermented liquors found as correct as the latitude of the being saccharine matter, I conclude question will allow. I have formed that, when the prices of these arti- it for my own use, and I may add cles are such as to render sugar the without exaggerating, that it is the more advantageous, as regards the result of trials made on several huiquantity of spirit to be obtained for dred guns. the same sum, there is no disadvan- To the second question I can give tage in using it largely as a partial no answer,

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FACTS IN GUNNERY. On the third I have to observe, tion of the whole charge of powder; that barrels are not so much dis. and that there is no loss of forcé tressed by firing balls if the bore is through the touch-hole, as in flintcylindrical; the shot having a ten- guns; and, also, that they redency to occupy a greater space, ceive the additional strength of the and therefore pressing hard against priming. the sides of the barrel. In proof of

dam, Sir, j'S this, the barrels of the guns used

Yours respectfully, with shot are soon leuded, owing to the friction of the shot; but this is

Wm. E. WIGHTMAN. not the case when balls are used. Malton, April 5th, 1825. The greatest objection, however, to the use of barrels of fowling-pieces

Charge of Charge of a for ball-shooting is, that they are

Calibre Powder forl Powder
cal

Quan- stance

of a Flint. for a Per. I tity of seldom sufficiently strong in the fore- Barrel. . Gun. cussion do. Shot. kill, end to prevent a vibratory motion, in which case the ball is thrown with 5-8 in.1 dram dram 11 oz, 30 yd out any degree of precision. A ball

140 of 19 to the pound exactly fits a 5-8ths bore, but a ball of 20 pounds, encircled in a thin piece of leather, 11.16 is preferable. « Telloc Trigger" is about correct in the quantity of pow. . der for charging it.

Fourthly, The Damascus barrels are decidedly superior to the stubs 3-4 twisted, or any other; the metal being stronger in texture, uniting better in welding, having little or no recoil, requiring a less charge of powder, and being more beautiful to

CORRESPONDENCE. the view; but, for a more particular account, see the Sporting Magazine Communications received from Mr. for April, 1824.

Reader--Ignoramus--C. X.--B. D." Telloc Trigger's" answer to the reference to contracted breeches is

A. N.-G. Smith-A Country Reader sufficient.

Engineer-Mechanicus---Mark AnvilThe percussion-lock has every ad. Legion-A Member of the Mechanics' vantage over the flint-lock, namely, Institution—Tutus-A Canadian-W.W. there is a less liability of accident by it, not being necessary to prime Stultus writes as if his name and chabefore loading, and the cock may be racter corresponded. We may probably always kept on the cap except at insert the paper he alludes to at some the moment of firing, which prevents the gun going off at half-cock; and

convenient opportunity; but it will be if the gun is brought home loaded. from a regard to the truth of the case, by taking off the cap (which is the and not to his indiscreet threats, priming), there is no danger of its being fired by the foolishness of Erratum.-Line 7, first column, p. 79, servants or others : and it is a fact, known to every observer of the per- .'

for 531. 88. 28d., read 55l. 88. 22d. cussion-gun, that they kill at ten yards farther than a flint-gun, and that about one quarter less powder Communications (pust paid) to be addressed to is used for a charge, owing to the

the Editor, at trie Publishers', KNIGHT and

LACEY, 55, Paternoster-row, London. complete and instantaneous combus. Printed by B. BENSLEY,Bolt-court, Fleet-street.

Mechanics Magazine, MUSEUM, REGISTER, JOURNAL, AND GAZETTE.

No. 91.]

SATURDAY, MAY 21, 1825.

[Price 3d.

“As the human mind is pleased with the contemplation of what is true, and delighted with the appearance of what is beautiful, it may be assumed that the cultivation of Science, and the • improvement of Art, originate in our love of pleasure.”-Ferro on the Fine Arts.

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SIR, I hope you will be pleased derstand it; and also for many me, to think this newly-invented Instru-' 'chanics and schoolmasters, for de. ment worthy a place in your “Me- monstrating problems in the highest chanics Magazine.” I presume, if branches of the mathematics. it were completely made, it would I am, Sir, a friend and well-wisher be found very useful at sea for navi- to mechanical sciences; and should gation, as any man might soon un- this be thought worthy your notice,

VOL. IV.

H

98

parts at

lie

DOUGHTY'S RUBY-POINTED PEN-BRICKS. I shall be happy to supply you with cond time the irregularity of endeavourmany of the latest inventions and im- ing to obtain that information which I provements in this part of the country.

foolishly thought no person of libera.

country., mind would feel disposed to deny me. I am, Sir,

. .., I am, Sir, respectfully yours, Yours, respectfully,

G. H.
HENRY OGLE,
• Schoolmaster, at Rennington, near
Alnwick, Northumberland.

BRICKS.
Description.

Sir,-Several answers have been soli.

cited by your Correspondent Rusticus, ABCD represent a plain piece of board, with a place in the middle,

"in No. 75, concerning Bricks. Will you

allow me to add to his inquiry a request

bu PP, for the slide, A, to move up and

for information on the nature of Pipe down in. Q is a quadrant made fast

Clay. Is it a fit substance to make bricks upon scale B. By enlarging this qua

of, where it can be obtained in great drant to a semicircle, QQ, the scales

quantity ? .. B and C, turning upon a centre, will set

Is there any cssential difference beto solve all questions in obliqué as well

tween the clay used for brick, and that as plane trigonometry. B will turn off

for pottery or crockery-ware, or is it from scale A to any distance, as at L, the pricked line; and by sliding A up

only a finer sort of which the latter ves wards or downwards in the board, the

sels are made?

Perhaps you will best reply to both of scales will set to the given dimensions of any triangle whatever, and give both

us, by pointing out some treatise on

brickmaking, if such there be.* the plane and the true contents of all

In the absence of scientific intelligence, he same time

I can inform Rusticus, that the red colour B to the pricked line, M, by a plummet hung at the centre, it becomes a good

in tiles and bricks is not always caused

by ferruginous matter : but those burnlevel; it will also give all the dimensions of a square. If you set slide A to the

ing white will, where they touch others

in the kiln, become red, and this red is dimensions of one side of a square, set

only on the surface, as may be seen by slide C to the same dimensions in the

breaking them : those bricks which are bottom scale, and C becomes the diagonal

red all through are probably of ferrugiof the square. I have solved all the pro

uous clays. Frost, before bricks are blems of practical navigation by this instrument, and a great number of promis

dried, is their greatest enemy; for even

on burning them afterwards, they becuous questions, with great ease and ac

come absolutely rotten, and will not curacy.

stand the least blow. N.B. The second horizontal line, C, and that next above it, represent a groove,

The Dutch very generally do over their

brick buildiugs with a mortar or plaster wherein a quadrant, QQ, slides, divided as the preceding; and by having two

mixed with oil and colour; blue, red, or quadrants and the four scales to move

light pink, and grey, are the most com

mon colours: when dry, such walls have upon the board ABCD, there will in all

a kind of gloss like varnish, and, of cases be three slides and two angles,

course, resist all wet. which, I presume, will solve any question

In the United States of North America, that can be proposed.

brick houses are painted afterwards ; they are not otherwise deemed finished. Red lead and Spanish brown are used.

Many of the brick houses in Englaud DOUGHTY'S RUBY-POINTED PEN.

admit ihe wet through the walls, from Sir, I shall be obliged by any of your the light, bad, porous quality of the Correspondents favouring me with the brick; especially when a shower of rain, address of the inanufacturer of this arti- mixed with snow, comes with a strong cle. I purchased one last year, and have wind. I have known an eighteen-inch found it answer very well; but having wall so penetrated quite through. The had an accident with it, and thinking I Dutch method of using coloured mortar, could suggest a trifling improvement by as above described, is certainly a better a personal communication with the mode of proceeding than the English maker, I applied for his address at the custom of using bad absorbing bricks, shop where I bought it, but was told by one of the partners that it was not regular to give it to me. I could not but * As good an article on Brickmaking think this rather contemptible, as I have as we remember to have met, is to be seen these pens in fifty shops in London, found in the Encyclopædia Metropoliand that they are therefore not made täna, whence it was extracted into our exclusively for that in question; I there- own pages (vol. 11. p. 76-79). It is from fore take this method of avoiding a se. the pen of Mr. Elmes, architect.

LOADING RIFLES-EXTINGUISHING FIRE ON BOARD SHIPS.

99

and not admitting them to be made wea- card, which fully confirmed my opi. ther-proof, for fear of losing their co- nion of the impropriety of using the Jour. The coating or covering can be of mallet in the above inanner. Now, any colour desired. Pug-mills are so numerous about Lon. as

an as it is necessary to have some effecdon, 1 advise Rusticus to examine them tive method to force the ball into for himself, which will answer his pur- the barrel (as the tight fitting of it pose better than any description I could is a sine quâ non to a good marksman), give. Clay alone will certainly make I should think that a short punch or bricks, but not all kinds of clay, though nearly all..

ramrod, with a concavity at one end : :

corresponding to the size of the ball, I remain, Sir,

covered over with leather (such as .. Your most obedient servant, are seen on some rifle ramrods),

TILLBROOK. inight be applied to the ball, while

the other extremity might be struck

with the mallet. This method (if LOADING RIFLES.

the punch be kept tight against the

ball) will never injure the form of Sir, It is the present practice among gun-makers to provide their

the ball. . When it has entered a few Rifle Gun-cases with a small wooden

inches into the barrel, the regular mallet, which is used in charging the

ramrod, with a similar concavity, rifle, to force the ball into the mouth

must be used, but it never should be

lifted up and down to strike the ball, of the piece, by several blows, as the

which should be sent home by presball, with the linen or leather (which is placed under it), is frequently too

sure, or it will never carry fair. large to be conveyed into the barrel

I am, Sir, by any other method. Now, as it (for the first time) must necessarily be acknowledged Your humble servant; by any person who has the least

T. M. M- N. knowledge of gunnery, that the direction of the ball is materially assisted by the perfectness of its spheri

EXTINGUISHING FIRE ON BOARD city, and as the upper part is flat- .

SHIPS. the mallet, it appears that this me

Sir,-From the many accidents of thod of forcing the ball into the bar- ships taking fire at sea, and these rel is, to say the least of it, ill

commencing in parts of the vessels judged. I was led to these remarks, not easily got at, it appears to me about a week ago, by happening to

that a reservoir, on deck, with pipes see some gentlemen trying rifies at

either of leather or lead, communiChalk Farin; one of them, who cer- cating and opening into various store tainly was a good shot. went several ruoins, such as the spirit-room, times rather wide of the mark, al. powder-room, &c. would be the though assisted with a rest. Those

means of procuring an instantaneous present iinagined there was some

application of water. The mouths defect in the position of the sights. Of

of the different pipes should be Lobserved, however, in my oren mind marked, so that only that which led (as suggestions are not always taken

to the part on fire should be opened. as well as intended), that, in charg

In my opinion this arrangement ing, the ball was very much flattened

would give passengers and all on by the use of the mallet, and I judged

board a very great assurance of that the gentleman would never make

safety; and I have no doubt the a certain shot while this was the case.

expense of it would be compenAt last I observed the ball go into

sated by the allowance the Insurance the barrel more easily, and ivithout Offices would make in favour of such being flattened at all; now, thought ships. I to myself, if he covers his object,

I am, Sir, he has a fair opportunity he fired . Your obedient servant, the ball, as I expected, shivered the

JB

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