VOL. XXXVl.] PHILOSOPHICAL TRANSACTIONS. 377 



Of a Lunar Eclipse, observed at Bologna, July 28, O. S. \T1Q. By Stg. 

 Eustachio Manfredi, M. D. F.R.S. iSc. W AW, p. 215. 



At 1 1*' 56™ 52' True time, the eclipse inad certainly begun. 



12 55 54 The total immersion of the moon. 



14 34 25 The beginning of the emersion. 



15 35 O The end of the eclipse. 



The same Eclipse observed at Rome. N°411, p. 217. 



At 12'' 1"" (V The shadow at the moon's limb. 



13 O l6 The total immersion. 



14 38 24 Beginning of the emersion. 



15 38 O The total emersion. 



A Catalogue of the 50 Plants from Chelsea Garden, presented to the Royal 

 Society, by the Company of Apothecaries, for the Year 1728; pursuant to 

 the Direction of Sir Hans Sloane, Bart. P. R. S. «^ Med. Reg. By Isaac 

 Rand, Apothecary, F.R.S. N° 412, p. 21 9. 



An Examination of Mons. PerauWs neiv-invented Axis in Peritrochio, said to 

 be entirely ivithout Friction. By J. T. Desaguliers, LL. D. N° 4 1 2, p. 222. 



Mons. Perault's account of his engine is as follows: " In imitation of the 

 modern crane, says he, I have invented two engines for raising weights. The 

 first is made of that organ which is the most advantageous of any in mechanics, 

 for facilitating motion; because it is free from that inconveniency which we 

 meet with in all others, viz. the friction of the parts of the machine, which 

 renders their motion more difficult. This organ is the roller, which Aristotle 

 prefers to all others, because all these, as wheels, capstans, and pulleys, must 

 necessarily rub in some of their parts. But the difficulty was to apply the 

 roller to an engine that raises weights, its use having only been hitherto to 

 cause them to roll on a horizontal plane. The engine which I propose has 

 a base aab, plate 8, fig. 7, something like the crane; having in its upper part 

 the horizontal piece b, which clasps an upright shaft co, supported under its 

 pivot c, on which the whole engine moves in the same manner as the crane, 

 when the weight is to be lowered. The shaft supports on its top a cross piece 

 DD, to which are fastened the ropes ee, which wrap round the barrel, axle, or 

 roller p, which has another rope g, also wrapping round one of its ends. This 



VOL. VII. 3 c 



