I5?0 On the Que/Hon, whether the Sunt Moon, and 



jnenon was obferved, in particular, during thofe remarkable 

 total eclipfes of the fun in the years 1706 and 1715. That 

 of the lathofMa^ 1706 was obferved in London by Hal- 

 ley; in Paris, by Caffini and De la Hire; at Montpellier, by 

 De Plantade; at Berlin, by Hofnrann; at Leipfic, by Baron 

 Von Wolf ; at Drefden, by Tfchirnhaufen ; ?t Nuremberg, , 

 by Wurzclbau ; at Jena, by Hambergcr ; at Zeitz, by Teu- 

 ber ; and at Breflau, by P. Heinrich. 



On this occafion Caffini, De la Hire, De Plantade, Wolf, 

 "VVurzelban and Heinrich obferved, during the greateft 

 darknefs, a light ring around the mooi\; but, on the other 

 hand, Hofmann and Teuber perceived nothing of the kind; 

 and thofe w.ho faw the ring differ very much from each othef 

 in the accounts they have given of its magnitude and colour. 



The eclipfe of the fun on the 3d of May 17 15 was obferved 

 at London by Halley and Louville in particular, and a ring 

 of the fame kind was obferved. Rings of the like kind have 

 been obferved alfp at various periods. 



2. Many allronomefs obferve, that the planets fometimes 

 when they approach the moon's limb have a coloured ap- 

 pearance, change their round figure, and feem to aflTume that 

 of an ellipfe. It has often happened that a planet at its ingref- 

 fion has appeared perfectly round, and at its egreffion quite 

 diftorled ; or, vice veij'a, diftorted at its ingreffion, and round 

 on its egreffion. The latter cafe I once obferved myfelf, in 

 ren-ard to Venus; the former was feen, in regard to Jupiter, 

 by M. Kaftner at Leipfic. This phenomenon takes place 

 not only with the planets but alfo with the fixed ftars, as is 

 proved by a multitude of inftances both old and new; fo that 

 it feems to be a faft eilabliflicd beyond all difpute. 



3. It is faid to have been remarked during folar eclipfes, 

 that the limb of the fun trembles before the moon entirely 

 touches it. 



4. The diameter of the moon is faid to have been obferved 

 fmall at the beginning and end of the darknefs durmg eclipfes, 

 and greater at the time of the greateft darknefs. On this cir- 

 cumftance Teuber founds his proof for the exigence of a 

 lunar atmofphere. Euler, from the diameter of the fun ap- 

 pearing 



