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SUGGESTED IMPROVEMENT IN PRINTING PRESSES.

345

4, the right leg, containing air from A to F.

MANAGEMENT OF Bees. ' 5 and 6, valves, having very small Sir, -Your valuable Magazine ones in their centres—they all open contains, in the Number published downwards.

the 9th ultimo, remarks on Bees. The whole apparatus supposed to be

Allow me to beg the favour of your air and water tight.

Correspondent to oblige, by addi

tional communication on the subject; The round figures represent hollow balls, which will sink one-fourth of

and I am sure many of your readers their hulk in water (of course will fall

will feel equally interested in any inin air) : the weight, therefore, of three formation he may give on his most balls resting upon one ball in water, as approved management of the beeat E, will just bring its top even with hive, in round-top hives, in the flat the water's edge; the weight of four hive, and under glass; and likewise balls will sink it under the surface the humble-bee; stating particularly until the ball immediately over it is the forin of hive best adapted for the one-fourth its bulk in water, when the latter, the time of procuring them under ball will escape rcund the corner from the fields, and the quantity of at C, and begin to ascend.

honey which may be obtained from The machine is supposed (in the them, when brought into a domestic figure) to be in action, and No. 8 (one state. of the balls) to have just escaped I ain, Sir, yours truly, round the corner at C, and to be, by

J. MEL. its buoyancy, rising up to valve No.3, striking first the small projesting valve

Wingham, Kent, Aug. 18th. 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

SUGGESTED IMPROVEMENT IN is opened (although only the size of a

PRINTING PRESSES. pin's head), No.2 valve will have taken Sir,-In the 95th Number of your upon itself to sustain the whole column

Magazine, I find a copy of a descripof water from A to B. The said ball (No. 8) having passed through the

tive drawing of Mr. Henry Russell's valve No.3, will, by appropriate weights

Improved Printing Press, which, on or springs, close; the ball will proceed

account of the advantages arising upwards to the next valve (No.2), and

from his peculiar application of Lord perform the same operation there. Stanhope's principle, the adjusting Having arrived at A, it will float upon screw, and his useful contrivance of the surface three-fourths of its bulk the wheel and rack, I consider to be out of water. Upon another ball, in an excellent piece of machinery, and due course arriving under it, it will be

well worth the consideration of those lifted quite out of the water, and fall

for whose service it is intended. But over the point D, pass into the right

my object in this paper is to suggest, leg (containing air), and fall to valve No.5, striķe and open the small valve

with your permission, something to in its centre, then open the large one,

Mr. Russell, which, if practicable, and pass through; this valve will then, will, I think, add considerably to by appropriate weights or springs, the general usefulness of his press. close, the ball will roll on through the I wish to ask that gentleman, if bent tube (which is made in that form he is acquainted with any small mato gain time as well as to exhibit chine that could be applied to his motion to the next valve, No. 6, where

press, to denote, with indexes, at it will perform the same operation, and then, falling upon the four balls at

any time the exact number of sheets E. force the bottom one round tbe pulled. I have been informed. that corner at C. This ball will proceed as

a machine, answering a similar pur. did No. 8, and the rest in the same pose, is now used in the toll-house, manner successively.

at the Strand Bridge ; but I ain I am, Sir,

quite ignorant of the principle of its

construction. It appears obvious to - Your most obedient servant,

me, that if this mode of numbering Philo Montis. were adopted in printing, it would

346

DENSITY OF THE EARTH-MEASURING HEIGHTS.

be found very convenient to the space be a plenum, the matter of workmen, as well as profitable to which moves the planets, resistance their employers and to the public. is equally out of the question. MatIt would entirely do away, in a print- ter filling space without being in moing-house, with what are called im- tion, seems contrary to the rigid perfections, or, at least, it would de economy of nature. Newton says tect the pressmen when they omit- space is empty; and if so, whence ted to regulate it, and consequently comes the resistance ? or is it on render them liable to be responsible some such account as this, that the for the deficiency in the number of mean density of the earth is sought sheets. It would likewise be a very after ? great saving to those publishers who

I am, Sir, are now obliged to use as waste paper

Your constant reader, nearly the whole of valuable copies of works, on account of the great

DUBLINI. expense of reprinting the parts wanting. The public, too, would be more

MEASURING HEIGHTS. certain of purchasing complete books; and this is of great importance where Sır,-Through the medium of the portions of a work are necessa- your valuable Magazine, permit me ' rily connected throughout. Persons to request your insertion of the fol. are often deceived with incomplete lowing general rule, in addition to copies at auctions, where they are what has been said in No. 67, p. 168, offered as being both new and perfect. on the Measuring of inaccessible

Heights and Distances, deduced from I am, Sir,

the equation there given. Your constant reader,

“ Multiply the given distance by

T.C-N. the least or farthest observation, and Derby, Aug. 24th, 1825.

divide the product by the difference between the two observations,” and the quotient will give the distance of

the object from the nearest station. DENSITY OF THE EARTH.

Thus the two observations being Sır,— The favour you have already

47 and 73, and the distance 40. conferred on me, in obtaining in 40 x 47=1880, and 2004 = 72.3= formation chrough your numerous enlightened Correspondence, oh se

KG; having which, the height may vera! subjects, makes me lament my

be found as there described. incapability of contributing in turn I think your Correspondent R. H. • to their edification. But as where will find that, in pructice, this rule little is given, little can be required; will be found not only more accuand, no doubt, where much is, freely rate, but more expeditious, than the will it be imparted. I request to be one he has proposed in No. 98, informed, wherein consists the utility p. 217, for finding, by trials, one. of uscertaining the mean density of the tenth of the height, the least inac. . eurth? My short-sightedness can see curacy of which must, of course, be no real utility in it, but as it is con: increased ten times. I therefore sidered a desiderutum in science, and conceive, it will be better to let the as so much learning has been dis- sights remain on the side AD, than played in solving the problem, there remove them to the side DB, which must certainly be much importance is the principal difference in the two connected with the answer, to which instruments; for it matters not whesuch great interest is attached. ther the shape be that of a quadrant

I conceive, that if space be a va or a square, farther than, as a square, cuum, and riatter perfectly inert, we perceive at once that the base is there is nothing to resist the panets; supposed to be divided into 10.100, neither can they resist whatever or 1000 equal parts; and that shape moves them. If, on the other hand, is also more convenient for con

SAFETY FROM CARRIAGES FALLING-SECRET IN SELLING. 347 structing a wooden frame with loose preferable to that described by Mr. mortice and tenon joints, that will Matthews, because the shafts being take to pieces and go into the pocket. thus supported, and prevented from I am, Sir,

coming to the ground, it will not Your most obedient servant,

only preserve the body of the vehiS. M.

cle nearly horizontal, but will, in August 16th, 1825.

the event of the horse stumbling, afford him a support, and enable him to recover himself-a desidera

tum which Mr. M. does in nowise SAFETY FROM CARRIAGES FALLING.

provide for. But the advantage of Sir,--Observing in your last supporting the shafts, over Mr. M.'s · Number a paper from Mr. Mat- plan, will be still more apparent when thews, the inventor of the Safety a horse falls in going down a steep Coach, on a contrivance for prevent- declivity, as it will then be evident îng accidents arising from Horses that the safety-irons will be of little falling with Two-wheeled Carriages, or no avail, in consequence of the I am induced to trouble you with the great declination of the road, and following observations on the same as the sudden stoppage would not subject.

fail to precipitate the person out of A premium having for some years the vehicle ; whilst, by the other meback been offered by the Society of thod, as the horse would be preArts, &c. for a similar invention, I vented from falling, the vehicle was led, four or five years ago, to wouid continue to move on, and turn my thoughts to this reward. consequently the danger of a sudden Now, as it must be evident, on the transition from motion to rest would slightest consideration, that the only be avoided. thing wanted in this case, in the

I am, Sir, yours truly, event of a horse falling, is to pre

T. BELL. serve, as nearly as possible, the ho.

Commercial-road, Whitechapel, rizontal position of the shafts, or the

Aug. 21st, 1825. 'body of the vehicle, I was very naa. turally led to adopt means to support

P.S. In my communication, page the former, for the reasons hereafter

270, col.2, 1. 13, for mechanics, read stated. I mentioned my idea to some

dea to some “ Mechanicus." of iny private friends, and amongst the rest, to that clever inathematician the late Mr. Anthony Cook, SECRET IN SELLING. Master of the Trinity House School, Newcastle, who expressed his high

Sir,- In Number 62, p. 94, is “A

Secret in Buying”-thirty-two galopinion of the utility of the inven

lons in winter, which will be thirtytion. I was, however, ultimately

three in summer. But perhaps the led to abandon the idea of commu

vessel in which it was measured may nicating the same to the Society, on

vury a little by that time. Permit considering the extreme simplicity of

me here to ask, is there not as great the contrivance-a thing which I

a secret in selling very light articles thought so self-evident, that had it

(which fetch a high price) by weight, possessed any merit, it would doubt

when and where the barometer stands less have been long before brought

very low? It would be conferring a into practice. I have since, how

service on the public, if any of your ever, been much gratified by observ

philosophical Correspondents would ing, in many instances, a modified

be so condescending as to make a sa. adoption of my plan, by the steps of

tisfactory calculation on this subject. gigs, &c. being placed more forward on the shafts, and approaching to

I am, Sir, within a few inches of the ground.

- Your obedient servant, This method I consider to be far

C. M.

( 348 )

MECHANICAL GEOMETRY.

(Continued from our last, page 334.)

THEOREM V.

AB, we have to show that the side In any triangle, if we draw a line BC will be divided in D, in the same parallel to any one of its sides, it proportion as the side AC is divided will divide the two other sides in the in E; that is, for instance, if BD samne proportion.

equals DC, AE will also be equal to Let ABC be any triangle, and let EC; that is (according to definition the line ED be drawn parallel to 6), as BD: DC :: AE: EC.

Let the triangle ABC be drawn, the same proportion, and this will and suppose, for instance, we divide hold good, whatever proportion the the side BC into two equal parts in lines CD and DB bear to each other; the point D, then is BD equal CD; for if we draw Ik parallel to ED, so now draw DE parallel to AB, then, that CK equals, for instance, the if we mechanically measure AE, we quarter of CB, IC will be equal a shall find it correspond to EC, or quarter of CA, for CE equals half that AC is also divided into two equal CD; and we have shown, that when parts in the point E.

CB is divided into two equal parts, Or, more geometrically, from B CA is divided also into two equal draw BF parallel to AC, and CF paparts; hence CI equals half CE, rallel to AB; then, if through D we and, of course, equals a quarter of draw DGH parallel to AC, we shall CA ; that is, as CK: CB :: CI: CA; have the two triangles, CDH and that is, the lines CB and CA are diBDE, identical, as the angle CHD is vided by the line IK in the same proequal to the angle BGD, and the portion, viz. as 1 to 4, which was to opposite sides are equal by construc- be shown. tion; and also the angle CHD is Cor. 1.-Hence, if we draw two equal to the angle BGD; and, of or more lines parallel to the base of course, the third angle at C and B a triangle, it will divide the other equal, they will correspond in two sides in the same proportion., all respects, or the remaining side C or. 2.-Hence, also, any line will also be equal; hence GD equals drawn in a triangle parallel to the GH, but DH equals HC, because base, cuts off another triangle from of the parallels HD and CH to the the vertex, similar to the original lines EC and ED, and GD equals triangle, for all the angles in the AE, for the same reason ; hence AE one are equal to all the corresponde equals EC; but BD equals DC, or ing angles of the other, and their the lines AB and BC are divided in sides proportional (hy Def. 21, Part

INQUIRIES

349 1.); for the triangle ABC is similar

HEATING ROOMS. to the triangle EDC or IKC, because the angles are all equal. and Sir, -I have for some time been the sides have (by this proposition) at great expense and inconvenience, been shown to be proportional.

from not being able to accomplish Cor. 3.-Hence, likewise, we see,

the heating a room with warm air that in similar triangles the sides

(impartially) to a sufficient degree, that are opposite the angles that are and should feel greatly obliged if equal to each other, are proportional you would allow my inquiry a place to each other ; that is, the side AC. in your useful Journal. in the triangle ABC, is to the side

What is the best means of attainEC, in the triangle EDC, in the

iny one hundred degrees of Fahrensame proportion as the side BC, in heit in a room of 12 feet square ?-the triangle ABC, is to the side CD. I have tried the design given in your in the triangle EDC; that is, as

49th Number, but find it insufficient AC:EC::BC: CD.

to my purpose. G. A. S. I should also be indebted, if Mr.

Vallance would favour me with a (To be continued.)

more explicit explanation of his principle upon that subject. The system

proposed in Number 35 does not RISE OF QUICKSILVER IN THE . procure the heat required. TORRICELLIAN TUBE.

I am, Sir, · SIR, I will be much obliged to

Your obliged servant, some of your numerous Correspond

D. C. ents to inform me, through the me Brighton. dium of the Mechanics’ Magazine, if it be the fact, which I have met recorded in some scientific work, the name of which, and particulars

INQUIRIE S. of the case, I have now no recollection of, that quicksilver stands supported, in a Torricellian Tube, at No. 140.--GILDING OLD PICTURE times, as high as seventy inches.

FRAMES. It is said to be only accidentally so, but the phenomenon cannot happen

SIR,- It would very greatly oblige without a cause; and when it is re

me if any of your intelligent.readers collected, that the barometer never

would inform me of the mode of ascends, from atmospheric pressure,

gilding old picture frames in oil to

gold-whether there is any method thirty-five inches (which one

of varnishing them with gold varwould suppose is the cause in both

nish, so as to look well and stand ? instances), I confess it puts my faith in the recital to no small trial. Se

The great expense of frames in this venty inches of quicksilver, giving

country deprives those who are not

rich of the pleasure of ornamenting seventy feet ascent of water, is what

their rooms with their own paintings no pump-sinker ever obtained yet.

or drawings, and consigns many a Being anxious to investigate the sub

good old family picture to the garret, ject, I have searched many philoso

from the shabbiness of its frame. phical works lately, but could meet nothing of the case ; yet being

It has occurred to me that some of

your ingenious Correspondents at, strongly persuaded it is mentioned

Birmingham might make frames of as having taken place, and, of course, is worthy investigation, I beg to so

metal, lackered as they do orna

ments for chairs, tables, &c. : ' they licit your publishing tliis my re

would be durable, light, and cheap. quest, to be informed whether it

Mouldings might be made of any con is tlie fact, and on what principles

venient length, and various breadths it takes place,

and patterns, so as to be cut and AS MY LAST HOPE. - jointed to any size wanted. Mould.

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