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THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[AUGUST) 



JIEMOIR OF M. BOUVARD. 



Extracted from the Eloge delivered by M. ./Ira go at the Funeral, 

 JuneU, 1S43. 



M. Bouvard, one of the seniors of the Academy of Sciences, and the 

 oldest member of the Board of Longitude, was born in 17G7, in a small 

 village of the Alps, near St. Gervais and Chamouny. His parents 

 were absolutely without fortune. At eighteen years of age, Bouvaid 

 had only the tail of the plough before him, or a muskot in the Sardi- 

 nian service, when he was luckily tempted to go to Paris. After some 

 objections and misgivings, prompted by natural atfection, a small pursi 

 was made up for him, and he walked up to Paris. It would be super- 

 fluous to enumeriite the difficulties to be encountered by a young man 

 without patrons, relations, or decided pursuit, and those feeble re- 

 sources were rapidly exhausted. It is enough to say that if Bouvard 

 did not get a dinner .-very day, no day did he fail to attend tlie gra- 

 tuitous and public lectures at 'the College de France. During several 

 months he hesitated between Matht-maUcs and Surgery — ^Mathematics 

 carried the day, his progress was rapid, and becoming an assiduous 

 auditor of Mauduit and Cousin, he soon had private pupils of his own, 

 among whom he was pleased to reckon M. de St. Aulaire, the French 

 Ambassador in London, and General Demarcay. Chance made M. 

 Bouvard a witness of the operations in the Observatory, and thence- 

 forth sprang up a complete passion for astronomy, (neither is this 

 term of passion inappropriate,) at a later period he was in an evi- 

 dently feverish state oi, the approach of any celestial phenomena, 

 •and the cloud which at the time of the eclipse of a star or satellite 

 threatened to deprive him of the sight of the Moon or of Jupiter, 

 threw him info despair. To the end of his life he related, with naire 

 regret, the eircumstauces which forty years ago had prevented him 

 from making certain observations ; at other times he would occupy 

 himseli with a task of logarithiras in his head for weeks and months, 

 trying to discover any faults of calculations which such or such assist- 

 ant in the observatory might have committed. In 1794 took plac^^ a 

 memorable event to him, an introduction to Laplace, who employed 

 him in the calculations for the Hh'caniqne Celente. He was thus suc- 

 cessively introduced as an assistant and member of the Board of Lon- 

 o-itnde, and member of the Academy of Sciences. It may be observed 

 that the fortune of the astronomer did not, however, much advance, as 

 the liberality of M. Bouvard towards a poor and numerous family kept 

 pace with his advancements; of the pleasures of society ^f. Bouvard 

 saw little, an experienced and able observer, he spent for many years 

 every clear night by the side of the instruments in the Observatory. 

 The General 'fable of Comets exhibits several of those stars the dis- 

 covery of which belongs lo him. Bouvard was a surprising calculator, 

 he went through friglitful masses of figures on many occasions, as 

 when occupied with the Theory of the Moon, in contending forapri/.e 

 of the first class of the Institute, which he divided with the celebrated 

 Burg of Vienna; as when engaged in constructing new table-; of Jupi- 

 ter, Saturn, and Herschel ; or, finally and principally, when obliged to 

 supply Laplace with the means of inserting in the Mrcanique Ct/fs/f 

 anything more than pure algebraic formula. His love of calculation 

 was indeed great, being occupied even of the evening before his death 

 in writing figures with a failing hand. 



of the plane extends 1| inch beyond the quarter circle, and the horizon- 

 tal plane (F) also extends three inches beyond that. 



Fig. I. 



A GATE HINGE. 



Description of a hinge for a coach-road gate ; commnnicnted by T. 

 N. Parker, Esq., A.M. 



This old fashioned manner of constructing the lower hinge of a 

 swing gate, if carefully managed, is as good a plan, if not better than 

 any other. The only objection that I am aware of is, that if the cir- 

 cular inclined plane is too steep, upon which the wheel or roller under 

 the heel of the gate is made to descend, the gate will shut with too 

 much violence, from an uniformly accelerated motion. 1 find that one 

 inch in six gives the proper fall on this inclined plane, for an entrance 

 aate to a carriage road, and where there is no lodge, with attendance. 

 This diagram shows that the upright round iron (A) of li inch dia- 

 meter is to be placed about 3 inches in the clear from the heel of the 

 gate (B), and an equal distance from the hanging post (C) ; and that 

 the distance from the centre of motion to the centre of the wheel (D) 

 on the heel of the gate is full fi inches. The inclined plane (E) is 

 rivetted on a plate of i inch iron, and 14 inches diameter, of which 3 

 inches are cut away in fitting it to the square face of the hanging 

 post (C) : it is secured on the ground by two screw-pins (G) of 5 dia- 

 meter fitting into the square holes shown in the diagram, and the pins 

 are leaded into limestone or freestone blocks, 



jfeS A straight vertical outline of one side or half the bar, or inclined 

 plane is given, fig. 2, which shows its length to be 15i inches, the two 

 asterisks marking the quarter circle at Hi inches, but the inclination 



As the inclined plane extends one inch beyouil the quarter circle, at 

 i; inches distance from the centre of motion, a gate lo feet long will 

 fall of itself, till the head of it is opened to about 20 inches beyond 

 the quarter circle, because as : 1 : ; 120 ; 20; but beyond that it 

 will be at rest, which is more safe ihan when a gate is held open by a 

 mail, on an unsteady horse perhaps. The bar or rail being thus prt- 

 pared, and about 1 inch in thickness, must be bent to the circular disc 

 and rivetted thereto. 



A short post, to prevent any strain on the hinges, should be placed 

 in the ground, near the head' of the gate, at 3 or 4 feet beyond the 

 quarter circle. It is reasonably to be expected that any one opening 

 the gate will have the grace to' put the gate in motion that it may 

 close itself, the same having been so constructed as to stand open a 

 little beyond the quarter circle, without being held open. The outline 

 of the sections of the heel of the gate, and the wheel, and the holes 

 for screw pins are given in the diagram. The weight and estimate 

 of this iron work may be fairly put down as follows :— 



Wheel and sockets, Sib. 'at Is Ss. rf. 



Rail and disc of wrought iron, 31i lb. at 4irf. (or of | 1 1 ;t 



cast iron at less tlian half that price) . . . . ) 



Or the whole of wrought iron, oVli lb. at Grf I'J ".I 



I have set up my own entrance gate in this manner, which answers 

 particularly well. The gate weighs about 300 lb. ; it will not fasten of 

 itself when the wind is strongly opposed to it, but the construction of 

 the iron work is excellent and substantial though necessarily heavy 

 and expensive. 



On this plan, the whole perpendicular weight of the gate rests ou 

 the ground instead of on the hooks; only the lateral strains of exten- 

 sion and compression are sustained for the most part where the two 

 thimbles attach. At inv entrance gate, I have had the posts a little 

 tapered, from I to 2 inc'hes in the diameters, and they are put up 

 corner-wavs, as represented by dotted lines at (C) in the diagram. 



If less 'fall should be preferred, the dip in tire place of fastening 

 might remain the same, and 3 inches of the rail might also be as at 

 present, then for 3, 4 or r> inches there might be a less fall, 1 in 12 

 instead of 1 in «, and the upper part of the inclined plane might still 

 a fall 1 in li. 



The two thimbles of § iron move up and down on a perpendicular 

 bar of iron li inch thick, nearly as long as the gate lieel ; and my 

 thimbles are fastened to the hanging post by hoops or straps of iion 

 fitting round the post, and at least one of the thimbles which belong to 

 the gate heel is moveable. 



The diagrams are drawn one-fourth the full size. 

 Sweenvy Halt, July Mth, 1844. 



I 



