410 ANNUAL OF SCIENTIFIC DISCOVERY. 



repeated divergence, that such men as Lalande, Cassini, Bouguer, etc., should 

 have committed mistakes amounting to several minutes of time, and mis- 

 takes, too, progressively varying from one period to another? This would 

 be absolutely impossible. But there is another curious circumstance, viz., 

 that by increasing the secular motion of the perihelion by thirty-eight seconds, 

 all the above observations are found to be correct to a second, and in some 

 cases even to half a second! M. Leverrier then proceeds to show, that in 

 order to explain this addition of thirty-eight seconds, we should have to 

 increase the mass attributed to Venus by one-tenth of its amount. This 

 mass, calculated to be the 400,000th part of that of the sun, has been however 

 found, by other calculations, rather too large, so that increasing it is out of the 

 question. Hence M. Leverrier concludes that the excess of the motion of 

 Mercury's perihelion must be owing to some other cause as yet unknown to 

 us, and this cause he supposes to be either a new planet, or a series of small 

 bodies circulating between the sun and Mercury. 



M. Faye, in commenting on this important communication, suggested that 

 all the astronomers of Europe should now direct their attention to the small- 

 est spots on the disk of the sun, in order to disco ver whether there Avere among 

 them any minute planetary bodies which had hitherto escaped observation. 

 Such bodies had often been looked after without success; but this proved 

 nothing, such researches having been made at mere hazard; now, however, 

 there were serious grounds for repeating such attempts, and total eclipses 

 would be the most advantageous periods for observing any minute body in 

 the immediate vicinity of the sun. A total eclipse, he added, would be visi- 

 ble in Spain and Algeria in July next. Suppose an astronomer at Campvey, 

 for instance, to prepare himself exclusively for such an observation, neglect- 

 ing everything else relating to the eclipse ; if a quarter of an hour before the 

 proper time he remained in a dark room, in order to guard his eyes from the 

 dazzling influence of the solar rays, whose effects continue for several min- 

 utes, and cause vision to be indistinct at the decisive moment, he might, as 

 soon as the eclipse has reached its maximum, observe the heavens with the 

 greatest accuracy, and perhaps discover what had hitherto escaped notice 

 under less favorable circumstances. 



Mr. E. C. Herrick, of Xew Haven, in a note communicated to Silliman's 

 Journal for Xov. 18-39, says : In this connection it may be worth while to 

 state that there are already on record observations which make it highly 

 probable that there exists an intra-Mercurial planet with a satellite. Wart- 

 mann reports (Bibl. Univ. Avr. 1837, p. 403; Quetdet: Corr. Math, et Phys., 

 Aug. 1837, p. 141) that Pastorff, of Buchholz, an attentive observer of the 

 solar spots, saw twice in 1836, and once in 1S37, two round black spots of 

 unequal size, moving across the sun, changing their place rapidly, and pur- 

 suing each time routes somewhat different. He found that the two bodies 

 observed Oct. 18, 1836, traversed an arc of 12' from 2 h 20 m to 3 h 12 m ; that 

 the two observed Nov. 1, from 2 h 48 m to 3 h 42 traversed in this time an arc 

 of 6'; and that the two observed Feb. 16, 1837, traversed an arc of 14', be- 

 tween 3 h 40 m and 4 h 10. In 1834, Pastorff saw two similar bodies pass six 

 times across the disk of the sun (Bib. Univ., t. 58). The larger was about 

 3" in diameter, and the smaller 1" 1"'25. Both appeared perfectly round. 

 Sometimes the smaller preceded the larger, sometimes the contrary. The 

 greatest observed distance between them was 1' 16".. The bodies were often 

 very near each other, and their transit then occupied only a few hours. 

 They had the appearance of a dull black spot, like that of Mercury in its 

 transits. 



