=

tion, 1x1; therefore x=.027 inches, the thickness of the metal required. But here it must be observed, that this rule fails when the metal is under a certain thickness, as the cylinder would then become flawed, and break with the smallest weight. The fact is, this reasoning is founded on the supposition that the figure of the section always remains circular, and will therefore only hold true under those limits in which the pressure upon the tube will not cause its section to change into another figure. Whether our tube falls under these limits or not, experiment only can determine, but it is very probable that it does not, as .027 of an inch is extremely thin.

In the above calculation I have considered both cylinders as composed of one kind of metal, which does away with the necessity of referring to tables on the relative strength of different metals.

No. 133.-CONSTRUCTION OF
BEE-HIVES.

SIR,-In your last week's publication there is an Inquiry, No. 133, "Construction of Bee-Hives," requiring information as to the best method of constructing, arranging, and sheltering flat hives, and the most proper time for depriving bees of a part of their delicious food?

As a practical apiarist, I beg to offer the information which my experience leads me to suppose the method best calculated for the management of bees in this country, with a view to their making the best return for the capital employed.

For the construction of flat lives we have ample directions from Huber (to whose indefatigable researches we are indebted for a complete key to the management

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of this valuable insect); but, as such a construction of hive is not congenial to the habits of the bee, nor do I think (except for experiment and instruction to the naturalist) they are suitable to our climate (which, by-the-bye, is what your Correspondent complains of), or fit to defend the inhabitants properly from the rigour of winter, I therefore rather approve of the common dome-topped hive in use in this country, first, because in its shape the bees are able to construct their combs in the best possible form for affording a safe retreat in the most severe winter, at the same time that their storecombs are within their reach without unnecessary exposure to cold; next, with these hives, a person having confidence in handling them, may appropriate to himself as much of their annual produce as can be spared without killing the bees, which, in every instance, must be a certain loss.

I have not had much time to spare for attending them, but have been able to take of their produce, in one year, 380 pounds of fine honey when my stock was 20 hives, saving alive double swarms in 10 hives for the winter; and as we know that bees do not live for two years, this is a strong argument in favour of saving them alive, and, from populous hives, the greatest advantage is reaped by early swarms in the following spring.

We cannot contemplate their beautiful work without wonder and delight; we even see that the angle at which the cells are formed on both sides of the comb of the common working bee, is that degree which fits them for holding the greatest possible quantity of their precious store. Let us husband our resources, save the lives of the little labourers, and look to future rather than immediate gain from their industry; resting assured, that being for a time contented with sharing a part, we shall ultimately have a tenfold return. Little farmers might well pay a small rent from the produce of their apiary.

I recommend the following method of taking the honey :-In the Yearly part of September ascertain the weight of each hive; those weighing of 40 p upwards are fit to live and to support two swarms; even 30 pounds be

is so conspicuous that it is easily done. The honey may be removed to a little distance, and if there are any bees left, they may be brushed off with a feather and they will are the companions. way t

I had 90 pounds of fine honey in the produce of a first

one

all at

that weight might be taken, and all heavy ones also. Having determined on the number to be taken, and on those to be left alive, place the hive to be taken on an empty hive, inverted, binding them round with a cloth, to prevent the escape of the bees; then let the full hive be turned upside down, and beat the sides with small rods till the bees shall have ascended into the empty hive, which will be accomplished in 10 or 15 minutes; then place the hive in which you intend they shall live for the winter on their stool, with a cloth spread down in front for a path, and the hive raised about an inch, for the reception of the new company; then, with a smart shake between your hands, let the whole swarm (which you have driven up into the clean hive) fall on the cloth. They immediately begin to ascend (very few venturing to fly), and, while they are so ascending, you are to secure the queen bee;.her removal will cause them to unite, whereas, if the queen is allowed to enter, the two queens must fight, and there is danger of losing both, besides great destruction amongst the common bees. The queen bee

term it) in this way the former year.

Besides the common working bee, I have had every description of humble bee, and even Wasps, working in hives in my garden.

1 have, I fear, encroached too much on your valuable pages; if, however, this reply is satisfactory to your Correspondent, and that it will be the means of increasing his store, I shall be gratified. I remain, Sir, Most respectfully yours,

June 28th, 1825.

CORRESPONDENCE,

Communications have been received from A Tinman-G. R.-C. D.-A Member of the Bolton Mechanics' Institute -T. M. B.-Mechanicus--Perseverantia -A Coustant Reader -A Carver and Gilder-O. F. F.-J. R. (Hythe)-Mr. Wightman-Sir J. Senhonse-A. B. S. Mentor-Isis-D. Z.-A Journeyman -Plummet-F. White.

PLAN OF EXTINGUISHING FIRES ON BOARD SHIP.

SIR,-I am of opinion with your Correspondent, J. B., in a late Num ber, that some effectual means ought to be provided in ships to prevent the recurrence of such a fatal disaster as that which befel the Kent East Indiaman; but I much doubt if water, sufficient to effect the extinction of flame proceeding from any considerable quantity of burning spirit, could be conveyed to the part on fire in the way J. B. proposes.

I herewith send a drawing, to explain a plan, which you will perceive is founded upon the principle, that air is necessary to support combustion.

The spirit-room must be air-tight, and lined with sheet copper or iron.

C, the injection-pipe, connected with a forcing-pump.-The ship's engine will answer the purpose.

D, a pipe leading to the well.

Suppose the interior of the room to be in flames; the hatch being put on, all

communication with the external air is

cut off, and the fire extinguished. Water is now forced into the room through the injection-pipe, C, which, condensing the rarefied air, allows the valve, H, to open, and the water to pass off by the pipe, D, into the well of the ship.

STEAM NAVIGATION.

SIR,-As Steam Navigation has lately become of great national importance, any contribution towards

its improvement, however small, may be considered a desideratum; it is with this idea that I venture to sub

mit to you a few remarks on the subject. All your Correspondents that have written on this subject hitherto, strongly object to the use of paddle-wheels. Now, in my opinion, the fault lies in the mode of constructing and applying them, and not in the paddle-wheels themselves, as I will endeavour to prove.»

paddle wheels to steam vessels, is to The common method of applying place them close to their sides, bý vessel is considerably retarded, by which their power of propelling the the quantity of water the vessel dis places constantly running to restore the equilibrium; add to this, the effect produced by the ridiculous practice of crowding a number of floats upon the wheels, and the loss of power must be considerable. I think these evils might be remedied, if the following plan were adopted :

Let the paddle wheels be made in two parts, each two-thirds the width of the common ones now in use; each part to have four floats fixed to it, at right angles to each other; let about three feet from the vessel's these two parts be fixed on the shaft, side, in such a manner that the floats shall be at an angle of 45 degrees from each other, by which means I imagine the paddle wheels would. lose none of their propelling power, which is not the case at present. Should I be in error, I shall be glad to be corrected by any of your more able Correspondents. I am aware it may be said, that the additional width of the paddle boxes would make the vessel appear cumbersome; but as I think it must be allowed that steam vessels do not, nor ever can, appear handsome, I hope this will not be considered an obstacle.

Should you think the above worthy a corner in your valuable miscellany, your insertion of it will much oblige,

Yours truly,

Rotherhithe.

R. FARLEY.

Set the length on C to 12 on D; then against the quarter girt on D is the solidity or content on Cin feet and tenth parts of a foot. wei Plai NOTE.

In order that the workmen may not be led into an error respecting this rule, it will perhaps be necessary to explain what is mentioned respecting the quarter girt, which is generally understood as that of a quarter of the length of a line that measures round the piece of timber; but the quarter-girt here mentioned is a geometrical mean proportional between the mean breadth and thickness, or it is the square root of the product of the breadth: multiplied by the thicknessy and it has been very pro perly observed by Hutton, in his Treatise on Mensuration, that unskilful measurers use the arithme tical instead of the geometrical mean, that is, half the sum of the breadth and thickness, which is always attended with error, and the more so as the breadth and thickness differ from each other,

We may here also observe, that if the piece of timber is tapering, that is, larger at one end than at the other ifit tapers regularly, we may measure the breadth and thick ness at the middle of the log, and if it does not taper regularly, but is unequally thick in some parts, and small in others, we must take several dimensions in different parts of the log, and add them together, and divide the sum by the number of measurements we have taken, which will be the mean dimensions.

EXAMPLE I.

What is the solid content of a square piece of timber, whose length is 14 feet, breadth 1 foot 6 inches, and thickness 1 foot 3 inches?

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First, then, we have to find the quarter girt, that is, a mean proportional between 18 and 15 inches, Then, by Problem v., the quarter girt is 16.43 inches, nearly.

Now per Rule.-Set 14 on C to 12 on D; then against 16.43 on D is 23 on C, very nearly, which shows the log to contain 23 solid feet.