DISCOVERY OP CERES AND PALLAS. 



numerical series in duple progression, there is nevertheless a cer- 

 tain approach to such a series, and at all events a glaring breach 

 of continuity between Mars and Jupiter. 



5. Towards the close of the last century, Professor Bode, of 

 Berlin, revived this question of a deficient planet, and gave the 

 numerical progression which indicated its absence in the form in 

 which it has just been stated ; and an association of astronomers 

 was formed under the auspices of the celebrated Baron de Zach, 

 of Gotha, to organise and prosecute a course of observation, 

 with the special purpose of searching for the supposed undis- 

 covered member of the solar system. The very remarkable 

 results which have followed this measure, the consequences 

 of which have not even yet been fully developed, will presently 

 be apparent. 



6. On the first day of the present century, Professor Piazzi 

 observing in the fine serene sky of Palermo, noticed a small star 

 of about the 7th or 8th magnitude which was not registered in 

 the catalogues. On the night of the 2nd Jan. again observing it, he 

 found that its position relative to the surrounding stars was sen- 

 sibly changed. The object appearing to be invested with a nebu- 

 lous haze, he took it at first for a comet, and announced it as such 

 to the scientific world. Its orbit being, however, computed by 

 Professor Gauss, of Gottingen, it was found to have a period of 

 1652 days, and a mean distance from the sun expressed by 2*735, 

 that of the earth being 1. 



By comparing this distance with that given in the preceding 

 table at which a planet was presumed to be absent, it will be seen 

 that the object thus discovered filled the place with striking arith- 

 metical precision. 



Piazzi gave to this new member of the system the name 

 CERES. 



7. Soon after the discovery of Ceres, the planet passing into 

 conjunction ceased to be visible. In searching for it after emerg- 

 ing from the sun's rays in March, 1802, Dr. Olbers noticed on the 

 28th a small star in the constellation of Virgo, at a place which 

 he had examined in the two preceding months, and where he 

 knew that no such object was then apparent. It appeared as a 

 star of the seventh magnitude, the smallest which is visible 

 without a telescope. In the course of a few hours he found 

 its position visibly changed in relation to the surrounding stars. 

 In fine, the object proved to be another planet, bearing a 

 striking analogy to Ceres, and what was then totally unprece- 

 dented in the system, moving in an orbit at very nearly the same 

 mean distance from the sun, and having, therefore, nearly the 

 same period. 



M 2 163 



