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1813.7 Great Solar Eclipse tn November 1816. 199

Horary motion of the D from the G in lier relative orbit 34' 299.4
Horizontal semi-diameter of the )

16' 271 Ditto of the o

16' 139.5 Sum of the semi-diameters of the and >>

32' 40".5 Longitude of the and ) at the time of true o

27° 0' 59 Horary motion of the ) in longitude

36' 49". Horary motion of the o in lougitnde

a $1". Horary motion of the ) in latitude

3' 21" Obliqnity of the ecliptic

23° 27' 52" Equation of time ato

14' 21".86 Horary motion of in R.A.= 2'36":5. O's R.A.- 234° 43' 14 Horary motion of in declination

34".8. The above elements are computed Flere follows the type and calculative from the best astronomical tables extant. of this eclipse for the latitude and meria The place of the o, and every particular dian of Greenwich. As this eclipse hope relating to that body, are calculated from pens at a great distance from the nona. the tables of M. de Lambre, and those for gesimal degree, and the latter having at che ) from the tables of M.Bury, for which, the same timre a considerable altitude in addition to the prize offered by the Board above the horizon, with B's laticude de of Longitude at Paris, he was very hando scending, the apparent contact of the somely rewarded by the late Empe. O's and D's limbs will take place very cor of France out of his private porse, for near the highest point of the O's peris this laboridus and invaluable performance. phery.

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defect will be observed to take place on Regiuiag Nov. 19, A.M. 8 23

the right hand at 180 184 58** from the Visible

9 19 49

vertical point of the O's timb. Middle, or Greatest Obscu. ration

9 23 51 * It appears that our correspondent's Ecliptic, or True

43 calculations of the Beginnings, Middle, End

10 35 50 End, and Digits, obscured, agree very near Daration

with those in the Nautical Almanac, but, in

% 15 27 Digits of the os diameter

the point of contact of the O's and (" eclipsed

9° 23' 37"

limbs, will respect to the vertical circle,

there is a considerable difference. Mr. Or superficial digits

8 45 16.4

Squire makes the contact to take place The eclipse begins at Greenwich about at abort 18° from the O'š vertex, whereas 374 after the o has riserrvid. at the Nantical Almanac states it at 590 fiori

the said point.---EDITOR, 3 18 23 A.T, at which time the first

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At 9 23 51, or the time of the great has less circumference, in proportion to

will be seen to be circular. The hexagon est obscuration, the centre of the D makes an angle with the vertical circle, with itself; as a simple proof of which I

its contents to any figure that will unite to the left hand, of 510 34' 36", at which add the following.. time the will be (vulgarly) 9 23 37 Every hexagon consists of 6 triangles, eclipsed on its north-easterly limb, but Every triangle contains 2 right angles.

Twice 6 is 12. Therefore, if one R. A. accurately 8 45 16.4 on the said

= 90, 12 R. A. 1080. Whatever limb. The eclipse will end at 10 33 50, number of lines meet in one point, they and the ) leaves the O's disc, on the are equal to 4 R. A. (15 Euclid;) there left hand, at 61° 8' 17" from its lower. fore, if one R. A. = 90, 4= 360. Take most point.

the points from the triangles, that is, The D's semi-diameter at the begin. take 360 from 1080, the remainder is ning is 16' 28", at the middle 16' 30", 720, which is the circumference of an and at the end' 16' 31":5, with the O's hexagon : 720 divided by the number semi-diameter 16' 13".5, and the dise of triangles, 6, makes the two angles of tance of their centres at the time of the each triangle by the circumference 120, greatest obscuration 7' 19".39.

One angle then is 60. If one line diIn the calculations of this eclipse for vide another straight line, the angles on Greenwich, I have ascertained thre lon. the two sides are equal to 2 R. A. = 180. gitude and altitude of the nonagesimal If one angle be 60, the other must be degree by spherical trigonometry, and 120; but 120 is the angle of an hexagon; the D's parallaxes, depending thereon, therefore it is the angle required to form from Dr. Maskelyne's excellent rule, another hexagon. In this manner, the given in Mr. Vince's quarto Astronomy, that it is the only figure, except the

other side may be proved, to shew also al page 67 of the first edition. In calculating the quantity of the square and triangle, that will unite with

itself. greatest obscuration of the present eclipse,

Hence, an bexagon has the perI have supposed the O's disc to contain section of a square, with less circum12 square digits, each digit to contain 60 ference to the same contents. The tri. square minutes, and each minute to con- angles also of an hexagon are equilateral tain 60 square seconds; agreeably to this Circumference of the hexagon and supposition, in the present case,

for
square being each

180

The solid contents of the hexagon 9 23 37 of the solar diameter, there will be

2430

The solid contents of the square will be only 8.75455, or 8 45 16.38

will be of the surface obscured.

2025 Epping; THOMAS SQUIRE.

That is, as 6 to 5 in favour of the

hexagon. Feb. 27, 1815.

Therefore, sir, if the proprietors of

land could divide their property into hesTo the Editor of the Monthly Mugarine. agons, there would be no odd pieces, SIR,

but a ring-fence to each, with the smalI

WISH, through your valuable mis- lest portion of bounds; sa if a city were cellany, to call the attention of men

built in hexagons there would be unity of science to the power (if I may use the and regularity, without a confined length word) of the hexagonal form. We have of passage to assist the force of ihe our circles, crescents, squares, octagons, wind; su hexagonal houses might have a and polygon's; but the utile dulci

appears

near neighbourhood without too close an to unite best in the hexayon, which may union, and more interior in proportion to be proved a circular concentration; for, the building, and hexagonal rooms would while a single circle is the most perfect have the like convenience without a figure, the hexagon is naturally formed

sameness of aspect. There are many from the union of circles. Thus, the

cases in which the hexagonal might be bee builds in the most perfect of forms; constantly used with advantage, such as for the divine gift inclines her to the pitching hurdles for sheep, where the lacircle, but, for the good of the commu.

bour of six days might be done in tive, nity, the union of cells forms the bex. and always at fairs for the pens; 80 I agon. To prove this, inspect an honey. conceive chimneys—but I have done. comb ; and all the cells of the exterior of Avebury, Marlbro',

C. LUCAS. she comb, where no pressure takes piace,

Dec. 1814.

For

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1815.1 A Morning's IValk to Rew-Fire-proof House. 201

For the Monthly Magazine. the inferior boards were actually charred, CONTINUATION of a MORNING'S WALK the less inflammable material of metal from LONDON to Kew.

prevented the process of combustion N entering Putney Ileath, the eye is from taking place in the superior boards. by the Kingston road-side, at the dis. both in different places, were not thicker tance of two hundred yards. It records a than tinfoil or cartridge-paper; yet, when wonder of the last age; and the liberal interposed between the double set of attention of the public authorities to a boards, they appeared to have answered discovery respectably, announced, and the purpose. which promised ulterior advantages 10 The House of Commons voted the community. Several destructive Fires 25001. to Mr. Hartley to defray the exin London bad led ingenious men to con- pences of this building; the sovereign sider of the means of preventing similar considered it a popular act to give himn catastrophes, One person improved water- countenance ; and a patriotic lord-mayor engines, another suggested floors of and the corporation of London, to im. stucco, and others contrived means of press the vulgar with deeper convictions escape; but David Hartley, esq. a son of its importance, witnessed the indeof the illustrious writer who traced to structible property of the structure on their sources the associations of Ideas, the 110th anniversary of the commenceand then a member of parliament, con. ment of the great fire of London. Yet trived to build a house which no applica- the invention sunk into obscurity, and tion of combustibles could consume. few records remain of it except the pom

This house, still standing at the distance pous obelisk and the wreck of this house. of a hundred yards from the obelisk, The American war converted Mr. Hart. serves as a monuinent of the inventor's ley into a patriot, and perhaps lost him plans; but, like every thing besides, it the confidence and favour of the court; recently excited the avarice of specula- or the expence of double floors; or the tion, and, when I saw it, was filled with idea of ponderous metallic plates; or workmen, who were converting it into a perhaps the little expectation which a man tasteful mansion, adding wings to it, who builds a house entertains that it is throwing out verandas, and destroying to be burnt, jointly or severally operated all vestiges of its original purpose. One of so as to prevent its adoption. Yet the the workmen shewed me into the room in evident security these sheets produce as which, in 1774, the King and Queen took coverings to joists and girders, and the their breakfast; while, in the room beneath, means they afford of cutting off the comfires were lighted on the foor, and various munication of the fungus, which destroys indanmable materials were ignited, to structures by dry-rot as certainly as fire prove that the rooms above were fire. itself, may still recommend them in cases proof. Marks of these experiments were where proprietors retain the direction still visible on the charred boards. In like of their own buildings, and are uncunmanner there still remained cbarred sure troled by the prejudices and cupidity of faces on the landings of the staircase, workmen. whereon fires had been lighted for the It merits observation that in moderna purpose of consuming them, but in vain; built Houses taste or accident has effectthough the stairs and all the foorings ed sufficient security against fire without were of ordinary deal wood! The fires any special preventives. Fire is only un. in the rooms had been so strong that governable when in its ascentit ineets with parts of the deal joists in the floor above combustible materials. Heat, as the prina were charred, though the boards in con- ciple of expansion, rarifies and volatilizes táct with them were in no degree pene, ali bodies ; and then, as the heavier give trated.

place to the lighter, so bodies subject to The alterations making at the mo. its action ascend, and carry up with them ment enabled me to comprehend the the principle, matter, or action of beat. A whole of Mr. Hartley's systen. Parts chief object therefore of man's policy in of the floors having been taken up, it economizing fire, in subduing it to his appeared that they were double, and use, and in governing its decomposing and that his contrivance consisted in intere destructive powers, should be to prevent posing between each set of boards, sheets its finding fuel in the ascent. No connectof laminated irou or copper. This me- ed timbers ought therefore to join an ille tallic lining served to render the floors ferior floor with a superior, so that, if air-tight, and thereby to intercepe the one Aoor were on fire, its feeble lateral ascent of the heated air, so that, alibough cumbustion might easily be extinguished MOSTULY Mag. No. 367.

D

with

with a mop and a pail of water, provided instruments of the keenest sufferings, no train of combustibles were extended the most frightful-sudden deaths, and to the floor above. Such is the language the most dismal domestic tragedies ! of philosophy, and such the slight pro. Yet the entire evil arises from the prin. cess of reason, by attending to which the ciple of the ascent of all heat; from the habitations of men may at all times be flame meeting in that ascent with fresh secured against the calamity of fire. How fuel to feed on, by which its intensity is absurd however was the construction of progressively augmented ; and then acie our houses till within the last twenty or ing at its summit on the head, throat, thirty years! Wooden staircases, ex- and sensitive vital parts of the agonized posed wooden balusters, and wainscotted victim. The remedy therefore is simply walls, coated with paints composed of to lie down, when the roaring flame of oil and turpentine, and put together more several feet high will be so reduced that like a train of combustibles, or a fire-ship it may be put out with the hands, with for objects of destruction, than the ha. the oiher parts of thegarments, or by any bitations of beings calling themselves extraneous covering. Tational! Ingenuity could in truth scarce- About a hundred yards from this fire. ly have devised a more fatal pile, which proof house stands the Telegraph which seemed to have been composed of com- communicates with Chelsea, and forms bustibles laid together and arranged for part of the chain from the Admiralty to the purpose of conflagration! The taste of Portsmouth and Plymouth. I found a modern architecture has however, without very intelligent man on the premises, intending it, corrected this evil. Stone and collected from him various facts in staircases, iron balusters, plastered walls, regard to these establishments. I learnt and lofty rooms, contribute to cut off the that there are twelve stations between communication, though a fire may have London and Portsmouth, and thirty.one seized on a flooring, or on any articles of between London and Plymouth, of which furniture. This security might however be eight are part of the Portsmouth line till further increased by more strictly regardthey separate in the New Forest. The other ing the principle; and by cutting off all chains extend from London to Yarmouth,

contact between floor and foor, made by formed by nineteen stations, and from wooden pilasters, window-shutters, &c., London to Deal formed by ten stations, by more liberal introduction of iron, and making in the whole sixty-four separate by the occasional use of Hartley's iron or telegraphs. The distances average about copper sheets; while nottring of orna- eight miles, yet some of them are twelve ment or utility need be sacrificed. or fourteen miles; and the distances are

By analogous reasoning it is suggests often increased by the want of commando ed to us, that, if those females whose ing heights. In the Yarmouth line par.. clothes have taken fire, and whose head, ticularly they make a considerable dethroat, breasts, and arm-pirs, are conse- tour northward. quently exposed to the increasing inten. After about twenty years' experience, sity of an ascending flame, were instant. they calculate on about two hundred ly to throw themselves into an horizontal days on which signals can be transmitted position, their vital parls would not only throughout the day; about sixty others not be affected, but the lateral fame on which they pass only part of the day, would be so trifling as to be easily and or at particular stations; and about one safely extinguished. What in human life hundred days in which few of the stati. can exceed in horror, the circumstance ons can see the others. The powers of of a woman, in full health, often in the the stations in this respect are exceedmiddle of her friends and family, being ingly various. The station in question is roasted alive by combustibles fastened generally rendered useless during easterly to her person, from which it is impossie winds by the smoke of London, which ble to escape till her most sensitive parts fills the valley of the Thames between have been reduced to a cinder! What this spat and Chelsea Hospital; or more crime ever perpetrated by human turpi- commonly between the shorter distance tude could have warranted such a faies of the Admiralty and Chelsea. Deaci What demons, contriving mischief and flats sere found to be universally unsa. torments, could have invented a com- vourable; and generally stations were bination of miseries so terrible and useless ir nearly the proportion of the heart-rending? The decorations of miles of dead flat looked over. On the beauty-the gratification of pridea-cven contrary, stations between hill and hill, the humble means of health and com. innking across a valley, or series of val. tort, are thus reudered the undercutul leys, vi tie mostly clear; and water surfaces

were

1815.) A Morning's IValk to KewTelegraph System. 203 pere found to produce fewer obscure days so that, without wcarying the eye, the than land in any situation. The period least motion of the distant telegraph might favourable of the same day was an hour have been exhibited on a plain surface, or two before and after the sun's passage and seen with both eyes like the leaf of of the meridian, particularly on dead a book. The application of optical inlevels, where the play of the sun's rays on struments, between a fixed station and, the rising exhalations rendered distant fixed object, ought to have been made vision exceedingly obscure. The still. in an original manner, and not influ. ness of the morning and evening were enced by the practices which prevail ascertained to be the most favourable in regard to moveable telescopes for hours for observation.

moving objects, The transmission of a message from

It concerned me to learn, that it was London to Portsmouth usually took place one of the first measures of the economy in about fifteen minutes; but, by an ex- of government, on the peace, to break periment tried for the purpose, a single up these demi.scientific establishments. signal has been transmitted to Plymouth The expence of 64 stations, at 1501. and back again in three minutes, which per annum, was but 10,000l. continuing. by the Telegraph route was at least five 50001. at half pay; and, if government hundred miles. In this instance however wanted them no longer, they might have notice had been given to make ready, and been devoted to the private service of every captain was at his post to receive individuals. I have long cherished and and return the signals. The speed was promulgated the opinion, that a system at the raie of one hundred and seventy of telegraphs, for doinestic purposes, miles in a minute, or three miles per se- would constitute the perfection of civi. cond, or three seconds at each station; a lization in any country. Multifarious facility truly wonderful! The number of are the occasions in which individual signals produced by the English telegraph interests require to be communicated is sixty-three-by which they represent with telegraphic celerity. The shipping. the ten digits, the letters of the alphabet, concerns alone would keep telegraphs many generic words, and all the numa constantly at work, between all ihe bers expressed by the combination of ports of the kingdom and Lloyd's coffeeibe digits sixty-three ways. The signals house; and commerce would be essen. are sufficiently various to express any tially served, if, during Change-hours at three or four words in twice as many London, Bristol, Liverpool, Hull and changes of the shutters.

Glasgow, communications could be maile The observers at these telegraphs are

to and fro' relative to the state of inarnot expected to keep their eye con- kets, purchases, sales, and other transstantly at the glass, but only to look actions of business. How convenient too every five minutes for the signal to make would be such a rapid intercourse beready. The telescopes are Dolland's (ween London and country bankers, Achromatics, at which one would wonder, in regard to balances, advances, and if every thing done for governments were money transactions; how desirable in not converted into a job. The intention law business between London and counshould have been to enable the observer try practitioners; and how important in to see the greatest number of times, and cases of bankruptcy or insolvency! In cousequently the ght sbould be inter. family concerns, notices of leaths, births, cepted by the smallest quantity of glass. accidents, progressive sickness, &c. it Dolland's Achromatics contain, howe would often be deeply interesting. The ever, six lenses, and possess no recom. state of elections, the issues of law. mendation but their enlarged field, and suits, determinations of the legislatheir freedom from prismatic colours ture, questions for answers, and numin that field, points of no consequence berless events of more or less im. in looking through a fixed glass at a portance, would occur to keep the fixed and circumscribed object. The telegraphs in constant requisition, so as field of the Galilean telescope is quite abundantly to repay the cost of conlarge enough, and, having but iwo lenses, structing and maintaining them, one of which is a thin concave, it gives A guinea would be cheerfully paid per the object with greater brightness, and 100 miles, for 5 or 6 words, which by pre. therefore ought to have been preferred concert might be transmitted in cypher. for this purpose. It seems strange too, Instead of sixty-four telegraphs, we might that, to ease the operator, it was never then require five bundred, and an esiacontrived to exhibit the fixed spectruin blishment costing 100,0001. per annum; on the principle of a portabie cainera, but five hundred messnges and replies

2 D ?

per

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