460 Opposition of Ceres. — Occultation. 



a diameter of 0"'7. He therefore considers himself justified in 

 ascribing to Ceres a diameter of about 1 620 English miles, 

 instead of the 163 of ^ ; to which he would add a height of 

 675 miles for an atmosphere of varying density and aspect, as 

 far as it could be traced with his 13-ffc. reflector. 



Such are the arguments of Schroter, in a very condensed 

 form ; and with all possible respect to the memory of one who 

 must ever be honoured among the greatest astronomers, it must 

 be admitted that they have a force which it is not easy to evade. 

 It is not indeed unlikely that he may have erred in excess ; 

 but still his approximation to truth is probably much closer 

 than that of his great rival. No subsequent measurement of 

 Ceres seems to be recorded,* nor does it appear upon what 

 grounds Humboldt has asserted that " the cometary clouds, in 

 which the small planets were at first supposed to be enveloped, 

 have disappeared on investigation with more perfect instru- 

 ments." It ought, however, to be mentioned that Laniont's 

 result with the sister planetoid Pallas, obtained with a great 

 (11 or 12 inch?) achromatic at Munich, giving it 670 miles in 

 diameter, instead of the 75 miles of ]j[, tends strongly to con- 

 firm the view of Schroter. 



We have ventured to give a large amount of detail in this 

 instance, from an impression that this curious discussion is but 

 little known, at least in England, and from a conviction that, 

 with the far greater optical advantages of the present day, the 

 true dimensions of this remarkable body, and the existence 

 and extent of its atmosphere, might be, and ought to be, more 

 correctly ascertained. 



OCCULTATION. 



Jan. 30, a Cancri, 4 mag., 8h. 39m. to 9h. 45m. (very 

 nearly at the time of Full Moon) . 



* Prof. Stampfer of Vienna is stated to have given measurements of 39 of the 

 Minor Planets by means of photometry, among which Ceres stands at 227 [Ger- 

 man or English Pj miles. The mode of procedure, however, can hardly lead to 

 any satisfactory result ; especially as in this instance it must involve the pre- 

 carious assumption of equality of reflective power and atmospheric transparency 

 in the objects of cxaminatiou. 



