VOL. L.] PHILOSOPHICAL TRANSACTIONS. K)l 



1 3° ; and the southern latitude of the perihelion also 1 3° : the ascending or north 



node ^ 4% in Scorpio ; and the comet's motion direct, or according to the 



order of the signs of the zodiac. On this supposition, he for some of the times 



of observations, estimated the apparent places of the comet, and found them as 



follows : 



LoDg. Latit. 



Sept. 18, at 3^ ante raerid. In s 18-^ and 9 deg. North. 



19 . . 4 25 22 8| 



22 . . 2i a 3| . . . . 6i 



23 .. 4 a 7| ....5^ 



25 . . 4| ^ 14f 4 



28 . . 4 SI 24^ . . . . 1| 



Oct. 4 . . 4| n)^ 9i 2 South. 



9 . . 4| lip 191 .... 3f 



11 •• 5 V)i 23| ....3| 



The observations which he took to ground the measurement on, are those of 

 the l6th and 23d of September, and of the 1st of October. It appears very 

 evident, not only from this rough calculation, but every other circumstance of 

 this comet, that it is not the same with that in the year l682, nor none of 

 those already calculated or brought upon a list, by Messieurs Halley and Struyk. 

 It is somewhat remarkable, that the line of the nodes is almost at right angles 

 with the longer axis of the ellipsis ; which corresponds nearly with the comets of 

 the years 1580, l683, and l686: but those had their perihelions northward of 

 the ecliptic ; whereas the perihelion of the last, which we have lately seen, was 

 to the southward of the ecliptic. 



LXI. On the Different Temperature of the Air at Edystone, from that observed 

 at Plymouth, between the Tthand 14th of July 1757. By Mr. John Smeaton, 

 RR.S. p. 488. 



Edystone is distant from Plymouth about l6 miles, and without the head- 

 lands of the sound about 11. The 7 th and 8th were not remarkable at Edystone 

 for heat or cold : the weather was very moderate, with a light breeze at east ; 

 which allowed them to work upon the rock both days, when the tide served. 



About midnight, between the 8th and gth, the wind being then fresh at east, 

 it was remarkably cold for the season. The wind continued cold the gth all day; 

 and so continued till the 1 0th ; when seeing no prospect of a sudden alteration 

 of weather, Mr. S. returned to Plymouth in a sailing boat, wrapped up in his 

 thick coat. As soon as they got within the headlands, he could perceive the 

 wind to blow considerably warmer ; but not so warm as to make his great coat 

 uneasy. Having had a quick passage, in this manner he went home, to the 

 great astonishment of the family to see him so wrapped up, when they were com- 

 plaining of the excessive heat : and indeed, it was not long before he had reason 

 to join in their opmion. 



