VOL. IX.3 PHILOSOPHICAL TRANSACTIONS. 1Q3 



all means, to graft good grafts upon such apple stocks as are produced from the 

 seed, and have been deprived of their heart-root, which shoots downwards. 



III. The Prevention of Poverty. Showing the Causes of the Decay of Trade, 

 Fall of Lands, and Want of Money: with Expedients for remedying the same, 

 and bringing the Kingdom to an eminent degree of Riches and Prosperity. By 

 Rich. Haynes, London, 1674, in 8vo. 



j1 more particular Account of the last Eclipse of the Moon, as promised in our 

 last Number. From the French Journal des Sgavans. N** 112, p. 257. 



January 11, N. S. 1675, about 5 o'clock, 12 min. in the evening, in the 

 Royal Observatory, M. Cassini, M. Picard, and M. Roemer, began to perceive 

 that the eastern part of the moon gradually lost its light ; so that at 5h. 25 m. 

 they saw a manifest penumbra; then at 5h. 32m. 50s. the limb over against 

 the spot called Hevelius grew so dark, that they all agreed that this was the true 

 beginning of the eclipse. They saw yet the little spot Riccioli, which disap- 

 peared not till 15 min. after; and so the shadow advanced from spot to 

 spot unto the other opposite limb of the moon, according to the regular order; 

 the most remarkable times and circumstances being as below ; viz. Beginning 

 of the eclipse at 5 h. 32m. 50s.; the total immersion 6h. 35 m. 46s ; beginning 

 of the emersion 8h. 8m. Os.; end of the eclipse gh. Qm. 40s. The diameter 

 of the moon, measured just before the eclipse, was 33' 15^'. The times were by 

 large pendulum watches, which were adjusted by the sun the same day, and 

 verified the day after ; besides, before the eclipse began, at 4h. 45m. 1 s. by the 

 watches, the star Capella was 45° high towards the east. 



Account of the Measure of the Earth's Meridian, By M. Picard. N° 11 1, p. 261. 



The sum of the whole of this account amounts to this: that M. Picard has 

 found 57060 toises for one degree, that is, 28 ^ leagues and 60 toises; which 

 being multiplied by 360, the number of the degrees, makes IO270 leagues and 

 1600 toises, reckoning 2000 toises to a league, or 2400 paces, 5 feet to a pace. 

 The method employed by him was, to measure on a plain and straight ground, 

 a space of 5663 toises or fathoms, to serve for the first basis to divers triangles, 

 by which he has concluded the length of a meridian line to be equivalent to a 

 degree. What is remarkable in this is, that no one ever measured so long a 

 basis; the greatest of the former observations having been but of 1000 toises;- 

 and that here have been employed, for taking the angles of position, very accu- 

 rate instruments, and telescopical sights, instead of common ones. 



M. Picard observes, that this problem, concerning the just dimensions of the 

 circumference of the earth, is no new thing; but has been the inquiry of seve- 

 ral ages, in which princes have been curious, and learned men encouraged to the 



VOL, II. C c 



