PRACTICABILITY OF MR. VALLANCE'S NEW MODE OF CONVEYANCE.

Sir,-Some of your correspondents having attempted to convince us of the practicability of Mr. Vallance's new mode of conveyance, and having, in my opinion, completely failed, I will endeavour, in a more explicit manner, to demonstrate to your readers, the feasibility of his plan. Let us suppose the tunnel to be seven feet diameter, and the airpump connected with the end thereof to be the same diameter, and let the piston travel at the rate of 200 feet per minute, (which is about the speed of a steam engine;) now it is evident that 200 feet of the tunnel will be exhausted in a minute, and hence, if we allow no friction to the carriage, and no escape of air by its sides, the carriage will travel at the same rate as the piston, viz. 200 feet per minute, or about 2 miles per hour. To effect this, it would evidently require a steam engine, whose cylinder has the same cubic content as the air-pump working with steam of the same pressure as the atmosphere, and connected at one end with the tunnel. Such a steam engine would be about 220 horse power; a very trifling affair no doubt. These considerations cause me very strongly to suspect, that certain deleterious drugs were introduced into the composition of the antidote administered by the Brighton Herald, which, however, we shall not swallow with the same avidity as Mr. Huald appears to have done.

Your's,

CHELMERIENSIS.

SELF-DEPOSITING DIBBLE WANTED.

Sir, One of the most important operations in agriculture is, the putting in of the seed-corn; and on the manner in which it is performed, the result of the future crop greatly de. pends.

With regard to wheat, the invention of the drill has, to a very great extent, superseded the tedious work of dibbling. As to the merits of the respective systems, much diversity of opinion exists among farmers;

15

but at the same time it is almost universally admitted, that the operation of dibbling is very imperfectly accomplished. The customary method is, for men and women with a dibble in each hand, to pierce the holes, and into these, the children who follow them drop the seed. Now it requires but little attention to perceive, that by this mode the most important part, the dropping the seed, is left to those who are the most unlikely to do it with the regularity and observation it requires. The consequence is, that upon examining their work, instead of there being two or three kernels in each hole, some have not any in them, others are nearly filled, and almost every variety of quantity is perceptible. Allow me, then, Mr. Editor, to enquire, if any of your readers are in possession of any plan or instrument, by which these defects may be avoided. It does appear to me, that the dibble might, in some way or other, be so constructed, as to leave, when withdrawn, the required number of kernels in each hole. This would be a saving of much labour and expense, and the invention itself would be a valuable boon conferred upon agriculturists. Genius is often employed upon far less worthy objects, and I feel confident that the inventor of a "self-depositing dibble," would find it a no unprofitable speculation.

I have been more particularly led to introduce this subject to your readers, as I have often, while walking over my lands to examine the young crops, felt the want of having in my hand some convenient instrument, by which the vacancies in the rows of the plants (whether drilled or dibbled,) occasioned by birds or insects, might be replenished with fresh seed. CERES.

TRANSFORMATIONS OF MATTER. Sir, I can find no excuse for troubling you, but the deep interest which I feel in the subject that I am going to write about.

When I saw F. M.'s question I looked upon it as a mere squib, or an indirect advertisement of Mr. Allen's lecture; and it had almost passed

16

from my mind before I saw Vindex's reply. Vindex pretends to settle the question between F. M. and Mr. Allen, and to prevent error on the subject for the future.

Now, sir, so far from Vindex setting me right, and preventing me from falling into error, he has put me wrong, and set my reason at variance with my faith, I being taught to believe that the body will be raised again at the day of judgment, and that the soul and body shall be re-united, and be exactly the same person that they were before. Vindex has succeeded so far with me as to convince me that my material body cannot be raised again, in its present form, after it is once decomposed. Ah! but where will this lead me? I have gone too far with Vindex! If the soul is necessary to the existence of the body, could the soul have existed without the body? How were they kept together, or what is the one without the other? I cannot conceive. But I may err through ignorance, as hard-working mechanics like me have but little time to study such subjects as this; but when our opinions are disturbed by Vindex in the Mechanics' Magazine, we are entitled to call upon the same to set us right again. Vindex and Mr. Allen have unsettled the established faith in the resurrection, and they must either prove that the soul is raised without a body, or declare with the materialist, and cease to talk of a spirit which they know nothing about. We see the mental parts of man frequently undergoing changes, so much, that in some men, we find those parts disordered, while others lose the use of them altogether; but still they exist, and are the same persons to all appearance; (let Vindex answer this; it is the part undergoing a change which he says undergoes no change.)

Perhaps Vindex will call this letter "palpable contradictions." Be it so; and so was his reply to F. M. I should not now have troubled you.

or

If you insert this in your magazine, it will perhaps call forth an explanation that will set us all right; but I hope the blind will not come to lead the blind, least we should all fall

P. S. Dec. 13. I have kept the foregoing remarks on Vindex's reply to F. M. till I have seen C. J.'s also. I see nothing in it, that calls for particular notice, except his admiration of different parts of nature, and his very minute description of the wing of a butterfly, whose quills would be small enough to make pens for the gentlemen of Ephemera, (as described in Dr. Franklin's Essays.) When we look narrowly into any one part of nature, we would think that that one part might command admiration above all the rest, did we not know that every other part deserves as much. While C. J. is in the meadow admiring the insect tribe, I would call his attention to some of the gay flowers which he is walking amongst, and see whether he cannot discover there, particles of matter as small, and more worthy of admiration, than that of a butterfly's wing; or he may turn to any other part of the grand whole, and he will find it equally deserving of his attention. G. W.

[We hope Vindex or Mr. Allen will speedily furnish G. W. with the answer which he requires. EDIT.]

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DESIGN FOR A SHOP WINDOW,

By Mr. M. Saul, of Lancaster

Sir, I send you a design of mine which I have lately executed, in the hope that you may consider it of sufficient interest to have a place in the Mechanics' Magazine. Nothing of the kind has hitherto appeared in its pages; yet it must be allowed that the subject of fitting up shop windows and doors is one on which much useful information might be given, were it taken up by your readers, so that those in the country might know the plans adopted in London, and those in London the plans adopted in other parts of the kingdom. The Laucaster police commissioners have lately begun to compel the removal of bow windows from the new street, and to cause them to be replaced by straight ones. The present design was executed, on that account, nearly in the centre of that street. Perhaps it may not be considered by some as any thing new; but to others it may appear both new and worthy of adoption. I would request your readers, in the first place, to consider whether it is any advantage to have a shutter on each side of the window, and the shutters made to hang behind the same? For my part, I regard it both as an ornament and a convenience; the front shutters turning on a centre at top and bottom, instead of hinges, ac

cording to the old plan. In the next place, I would direct the attention of your readers to the plan of the cornice. It will be found to consist of very few moulds; but I have found that turned beads may be introduced both into cornices and moulds for doors, which will be found to have a good effect.

Description of the Drawings.

The drawing in front represents an elevation of the window. The cornice projects 9 inches from the wall; the top square is 5-8ths; the beads under the top square 7-8ths by 1 inch long; the quirk; the ovalo 1 inch and 1-8, and projects 14 inches; the 2 squares and inch. The projection under them goes backward 2 in. and 3-8ths for the blocks; they are cut bevel-wise, and the end that goes against the square is 3-8, and the other end 7-8; the beads under the square and blocks are 5-8 by 1 inch long. The frieze is 6 inches, and inclines forward about of an inch, which gives a good effect to the letters. The square below the frieze projects 5-8, and shows a square of 3-8ths. The beads are 1 inch long, and the square below 3-8ths. These beads are glued up in two pieces, with a piece of paper in the joint, so that when they are turned, they are easily parted. For these, and also those round the shutters, a groove is made an inch deep, and broad, to receive them as bead and flush.

The figures at the bottom of the preceding page, show the plan of the shutters. A, is fast, and projects 34 inches from the wall, and shows 1 in front, allowing 2 squares of 3-8ths each, and for the bead; B, is the broad stile, to correspond with the other side; C, is the sash stile; D, is the form of the iron bar end, that hooks into the stile, C, and meets in the middle of the window; a bolt passes through them into the inside, where it is secured; E, is let into the edge of the shutter stile; B F, is let into G, for F, to work in. There are three loose shutters besides those two on each side, on account of being only allowed 34 from the front of the wall.

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TRAVELLER'S AND MAIL GUARD'S CORRECTOR;

Shewing the difference in time be

tween London, and One Hundred Principal Towns in Great Britain.

We now present our readers with the second table, furnished to us by our correspondent, Mr. J. G., p. 546, Vol. 6. The great accuracy with which the rate of the Mail Coaches, and of many Stage Coaches, is adjusted to time, renders it important that equal exactness should be observed at the different post offices and posting_houses throughout the kingdom. This table is intended to facilitate that object, shewing the proper allowance to be made for differences of time, at the towns through which the coaches pass.

17 do.

Penzance

22 do.

Berwick

.

8 do.

Bangor

16 do.

Brighton

Grantham Harwich

2 do.