554 COSMOS. 



still this term is preferable to that of comets of short period, 

 from the fact that it is in each epoch of our knowledge 

 dependent upon something definite. The six interior comets 

 now accurately calculated, certainly vary in their periods of 

 revolution only from 3*3 to 7*4 years; but if the return of the 

 comet discovered by Peters at Naples, upon the 26th of June, 

 1846 (the 6th comet of the year 1846 with a half-major axis 

 of 6'32), after a period of 16 years, should be confirmed, 80 it 

 may be foreseen that intermediate members, in reference to 

 the duration of the period of revolution, will gradually be dis- 

 covered between the Comets of Faye and Olbers. Then it 

 would be difficult in future to fix a limit for the shortness of 

 the period. Here follows the table in which Dr. Galle has 

 arranged the elements of the six interior comets. 



** Galle, in Olbers' MetTiode der Cometenbahnen, p. 232, 

 No. 174. The comets of Colla and Bremiker of the years 

 1845 and 1840, present elliptical orbits with proportionately 

 not very short periods of revolution. (I allude to the 3065 

 and 8800 years of the Comets of 1811 and 1680). They 

 appear to have periods of revolution of only 249 and 344 

 years. (See Galle, op. cit. pp. 229 and 231.) " 



