NEW APPLICATIONS OF THE LEVER POWER. continuing to act on the stream after its passage through the orifice, by which continued pressure the stream acquires a progressive increase of velocity, until its discharge from the extremity of the tube. That more water should flow in a given period through a diverging conical tube, than through a straight one, is, perhaps, owing to the friction of the stream being less in the former than in the latter; but care should be 343 taken that the tube be not so wide as to allow the admission of air into it whilst the water is flowing. if Such are my ideas on this subject; they be erroneous, I shall feel indebted to any of your Correspondents who will correct them. Your Redruth. I am, Sir, very humble servant, P. E. SIR, The unsuccessful (but far from fruitless) search made to discover the philosopher's stone," and the "elixir vitæ," were productive of most important and beneficial results in the kingdom of chemistry; so, by a parity of consequence, I am disposed to believe that, froin inquiry after the "perpetual motion" (though equally unsuccessful), a similar good will result to the mechanical world. After this apology for those who may sometimes think (and myself amongst the number) upon this much ridiculed, and now almost totally exploded, subject, I beg leave to offer to your notice, and for the momentary amusement, perhaps, of some of your readers, the prefixed device. The point at which, like all the rest, it fails, I confess I did not (as I do now) plainly perceive at once, although certainly it is very obvious, and will be, no doubt (as I shall leave it to be), immediately pointed out by some of your Correspondents. The original idea was this-to enable a body which would float in a heavy medium and sink in a lighter one, to pass successively through the one to the other, the continuation of which would be the end in view. To say that valves cannot be made to act as proposed, will not be to show the rationale (if I may so say) upon which the idea is fallacious. The figure is supposed to be tubular, and made of glass, for the purpose of seeing the action of the balls inside, which float or fall as they travel from air through water, and from water through air. The foot is supposed to be placed in water, but it would answer the same purpose if the bottom were closed. Description of the Engraving. No. 1, the left leg, filled with water from B to A. 2 and 3, valves, having in their centres very small projecting valves-they all open upwards. SUGGESTED IMPROVEMENT IN PRINTING PRESSES. 4, the right leg, containing air from A to F. 5 and 6, valves, having very small ones in their centres-they all open downwards. The whole apparatus supposed to be air and water tight. The round figures represent hollow balls, which will sink one-fourth of their bulk in water (of course will fall in air); the weight, therefore, of three balls resting upon one ball in water, as at E, will just bring its top even with the water's edge; the weight of four balls will sink it under the surface until the ball immediately over it is one-fourth its bulk in water, when the under ball will escape round the corner at C, and begin to ascend. The machine is supposed (in the figure) to be in action, and No. 8 (one of the balls) to have just escaped round the corner at C, and to be, by its buoyancy, rising up to valve No. 3, striking first the small projecting valve in the centre, which, when opened, the large one will be raised by the buoyancy of the ball; because, the moment the small valve in the centre is opened (although only the size of a pin's head), No. 2 valve will have taken upon itself to sustain the whole column of water from A to B. The said ball (No. 8) having passed through the valve No.3, will, by appropriate weights or springs, close; the ball will proceed upwards to the next valve (No. 2), and perform the same operation there. Having arrived at A, it will float upon the surface three-fourths of its bulk out of water. Upon another ball, in due course arriving under it, it will be lifted quite out of the water, and fall over the point D, pass into the right leg (containing air), and fall to valve No. 5, strike and open the small valve in its centre, then open the large one, and pass through; this valve will then, by appropriate weights or springs, close, the ball will roll on through the bent tube (which is made in that form to gain time as well as to exhibit motion) to the next valve, No. 6, where it will perform the same operation, and then, falling upon the four balls at E, force the bottom one round the corner at C. This ball will proceed as did No. 8, and the rest in the same manner successively. I am, Sir, Your most obedient servant, PHILO MONTIS. MANAGEMENT OF BEES. 345 SIR,-Your valuable Magazine contains, in the Number published the 9th ultimo, remarks on Bees. Allow me to beg the favour of your Correspondent to oblige, by additional communication on the subject; will feel equally interested in any inand I am sure many of your readers formation he may give on his most approved management of the beehive, in round-top hives, in the flat hive, and under glass; and likewise the humble-bee; stating particularly the form of hive best adapted for the latter, the time of procuring them from the fields, and the quantity of honey which may be obtained from them, when brought into a domestic state. I am, Sir, yours truly, SUGGESTED IMPROVEMENT IN SIR,-In the 95th Number of your Magazine, I find a copy of a descriptive drawing of Mr. Henry Russell's Improved Printing Press, which, on account of the advantages arising from his peculiar application of Lord Stanhope's principle, the adjusting screw, and his useful contrivance of the wheel and rack, I consider to be an excellent piece of machinery, and well worth the consideration of those for whose service it is intended. But my object in this paper is to suggest, with your permission, something to Mr. Russell, which, if practicable, will, I think, add considerably to the general usefulness of his press. I wish to ask that gentleman, if he is acquainted with any small machine that could be applied to his press, to denote, with indexes, at any time the exact number of sheets pulled. I have been informed, that a machine, answering a similar purpose, is now used in the toll-house, at the Strand Bridge; but I am quite ignorant of the principle of its construction. It appears obvious to me, that it this mode of numbering were adopted in printing, it would 346 DENSITY OF THE EARTH-MEASURING HEIGHTS. be found very convenient to the workmen, as well as profitable to their employers and to the public. It would entirely do away, in a printing-house, with what are called imperfections, or, at least, it would detect the pressmen when they omitted to regulate it, and consequently render them liable to be responsible for the deficiency in the number of sheets. It would likewise be a very great saving to those publishers who are now obliged to use as waste paper nearly the whole of valuable copies of works, on account of the great expense of reprinting the parts wanting. The public, too, would be more certain of purchasing complete books; and this is of great importance where the portions of a work are necessarily connected throughout. Persons are often deceived with incomplete copies at auctions, where they are offered as being both new and perfect. I am, Sir, Your constant reader, Derby, Aug. 24th, 1825. T. C-N. DENSITY OF THE EARTH. SIR,-The favour you have already conferred on me, in obtaining information through your numerous enlightened Correspondence, oh severa! subjects, makes me lament my incapability of contributing in turn to their edification. But as where little is given, little can be required; and, no doubt, where much is, freely will it be imparted. I request to be informed, wherein consists the utility of ascertaining the mean density of the earth? My short-sightedness can see no real utility in it; but as it is considered a desideratum in science, and as so much learning has been displayed in solving the problem, there must certainly be much importance connected with the answer, to which such great interest is attached. I conceive, that if space be a vacuum, and riatter perfectly inert, there is nothing to resist the planets; neither can they resist whatever moves them. If, on the other hand, I think your Correspondent R. H. will find that, in practice, this rule will be found not only more accurate, but more expeditious, than the one he has proposed in No. 98, p. 217, for finding, by trials, onetenth of the height, the least inaccuracy of which must, of course, be increased ten times. I therefore conceive, it will be better to let the sights remain on the side AD, than remove them to the side DB, which is the principal difference in the two instruments; for it matters not whether the shape be that of a quadrant or a square, farther than, as a square, we perceive at once that the base is supposed to be divided into 10.100, or 1000 equal parts; and that shape is also more convenient for con SAFETY FROM CARRIAGES FALLING-SECRET IN SELLING. SAFETY FROM CARRIAGES FALLING. SIR,--Observing in your last Number a paper from Mr. Matthews, the inventor of the Safety Coach, on a contrivance for preventing accidents arising from Horses falling with Two-wheeled Carriages, I am induced to trouble you with the following observations on the same subject. A premium having for some years back been offered by the Society of Arts, &c. for a similar invention, I was led, four or five years ago, to turn my thoughts to this reward. Now, as it must be evident, on the slightest consideration, that the only thing wanted in this case, in the event of a horse falling, is to preserve, as nearly as possible, the horizontal position of the shafts, or the body of the vehicle, I was very naturally led to adopt means to support the former, for the reasons hereafter stated. I mentioned my idea to some of my private friends, and amongst the rest, to that clever mathematician the late Mr. Anthony Cook, Master of the Trinity House School, Newcastle, who expressed his high opinion of the utility of the invention. I was, however, ultimately led to abandon the idea of communicating the same to the Society, on considering the extreme simplicity of 'the contrivance-a thing which I thought so self-evident, that had it possessed any merit, it would doubtless have been long before brought into practice. I have since, how ever, been much gratified by observing, in many instances, a modified adoption of my plan, by the steps of gigs, &c. being placed more forward on the shafts, and approaching to within a few inches of the ground. This method I consider to be far 347 preferable to that described by Mr. Matthews, because the shafts being thus supported, and prevented from coming to the ground, it will not only preserve the body of the vehiele nearly horizontal, but will, in the event of the horse stumbling, afford him a support, and enable him to recover himself-a desideratum which Mr. M. does in nowise provide for. But the advantage of supporting the shafts, over Mr. M.'s plan, will be still more apparent when a horse falls in going down a steep declivity, as it will then be evident that the safety-irons will be of little or no avail, in consequence of the great declination of the road, and as the sudden stoppage would not fail to precipitate the person out of the vehicle; whilst, by the other method, as the horse would be prevented from falling, the vehicle would continue to move on, and consequently the danger of a sudden transition from motion to rest would be avoided. I am, Sir, yours truly, T. BELL. Commercial-road, Whitechapel, Aug. 21st, 1825. P.S. In my communication, page 270, col.2, 1. 13, for mechanics, read "Mechanicus." SECRET IN SELLING. SIR,-In Number 62, p. 94, is "A Secret in Buying"-thirty-two gallons in winter, which will be thirtythree in summer. But perhaps the vessel in which it was measured may Permit vary a little by that time. me here to ask, is there not as great a secret in selling very light articles (which fetch a high price) by weight, when and where the barometer stands very low? It would be conferring a service on the public, if any of your philosophical Correspondents would be so condescending as to make a satisfactory calculation on this subject. I am, Sir, Your obedient servant, C. M. |