221 



near its descending node at the former period, and near its ascend- 

 ing node at the latter. 



After the announcement of this singular discovery, it was found 

 that other observations of a like kind had been previously made. 

 Several instances are collected by Professor Wolf in the tenth num- 

 ber of his Mittheilungen iiber die Sonnenflecken, eight of which are 

 quoted in vol. xx. (p. 100) of the Monthly Notices of the Royal 

 Astronomical Society. Two of these, the observation of Stark on 

 October 9, 1819, and that of Jenitsch on October 10, 1802, agree 

 sufficiently well with the calculated position of the node of the object 

 seen by Lescarbault. But the spot seen by Stark is stated to have 

 been about the size of Mercury. 



Capel Lofft saw at Ipswich, on January 6, 1818, at 11 a.m., a 

 spot of a ' sub-elliptic form,' which advanced rapidly on the sun's 

 disk, and was not visible in the evening of the same day (Monthly 

 Magazine, 1818, part 1, p. 102). 



Mr. Benjamin Scott, Chamberlain of London, saw about mid- 

 summer of 1847 a large and well-defined round spot, comparable in 

 apparent size with Venus, which had departed at sunrise of the next 

 day (Evening Mail, January 11, I860). 



PastorfF of Buchholz records that he saw on October 28 and 

 November 1, 1836, and on February 17, 1837, two round black 

 spots of unequal size, moving across the sun at the respective hourly 

 rates of 14', 7", and 28'. Also he announced, January 9, 1835, to 

 the Editor of the Astronomische Nachrichten, that "six times in the 

 previous year he had seen two new bodies pass before the sun in dif- 

 ferent directions and with different velocities. The larger was about 

 3" in diameter, and the smaller from 1" to 1"'25. Both appeared 

 perfectly round. Sometimes the smaller preceded, and at other 

 times the larger. The greatest observed interval between them was 

 1' 16": at times they were very near each other. Their passage 

 occupied a few hours. Both appeared as black as Mercury on the 

 sun, and had a sharp round form, which, however, especially in the 

 smaller, was difficult to distinguish." Schumacher considered it his 

 duty as editor to insert the communication, but evidently did not 

 give credit to it (Astron. Nachr. No. 273). 



In vol. ii. of the Correspondence between Olbers and Bessel, 

 mention is made in p. 162 of an observation at Vienna by Steinhiibel, 

 of a dark and well-defined spot of circular form which passed over 

 the sun's diameter in five hours. Olbers, from these data, estimates 

 the distance from the sun to be 0"19, and the periodic time thirty 

 days. It is remarkable that Stark saw about noon of the same day 

 a singular and well-defined circular spot, which was not visible in 

 the evening. This is one of the instances in vol. xx. of the Monthly 

 Notices of the Astronomical Society. 



These accounts appear to prove that transits of dark round objects 

 across the sun are real phsenomena ; but it would perhaps be prema- 

 ture to conclude that they are planetary bodies. If the object ob- 

 served by Lescarbault be a planet, it is certainly very surprising that 

 it has not been often seen. Schwabe, after observations of the sun's 



