126 



SCIENCE. 



[N. S. Vol. XII. No. 291. 



A comparison of these two last columns 

 with the corresponding ones of the observed 

 values shows that except in the case of the 

 Andromedid meteor on ISTovember 24th, 

 both the apparent and true observed values 

 of the velocity are much smaller than those 

 derived on the assumption of a cometary 

 velocity. The former (the observed) veloc- 

 ities lead to orbits of a very improbable 

 character having periods of from 1.25 to 

 1.80 years, so that it would seem an almost 

 certain conclusion that the atmospheric re- 

 tardation has amounted to from 8 to 15 

 km. per second for the four meteors. On 

 the other hand the Andromedid of N"ovem- 

 ber 24th furnishes the following orbit, by 

 the side of which is placed that of Biela's 

 comet according to Hubbard : 



Meteor Nov. 24, 1899. 



Biela Comet. 



7T- = 108°48'-) T=109 



i2 = 242 22 n875.0 S2 



: 12 4 J 



= 0.7923 

 = 4.110 



245 51 n 852.0 

 i = 12 33 1 

 e = 0.7559 

 a =3.526 



Rather unfortunately this Andromedid 

 trail is at the very edge of the plate, and 

 therefore somewhat ill-defined, so that the 

 length of the single interruption available is 

 somewhat uncertain. If this be changed 

 by 19" from the original measurement, or 

 about Jg of a millimeter on the plate, a 

 quantity which is, perhaps, admissible un- 

 der the unfavorable circumstances, an exact 

 agreement with the cometary elements ' a ' 

 and ' e ' can be brought about. 



This remarkable circumstance makes it, 

 therefore, again somewhat questionable 

 whether the small velocities found for the 

 other four meteors may not after all be 

 somewhere near the cosmic values and the 



truth will have to await accumulated evi- 

 dence. Especially valuable will be a long 

 trail with considerable change in altitude 

 and a large number of sharp interruptions. 

 The only one of our trails which has more 

 than two such breaks is the one of August 

 7th, where three values of the velocities can 

 be deduced. These are, in the order of the 

 meteor's progress, and descent, 12.33, 12.11 

 and 12.09 km. per second, which, while 

 showing an increased retardation, hardly 

 admit of any definite conclusions. As I 

 have just said, more data are necessary and 

 we hope to secure them and also increase 

 the accuracy in the near future. 



Recent Astronomical Work at Columbia Uni- 

 versity: By Haeold Jacobt. 

 Professor Rees, director of the Columbia 

 University Observatory, being absent at 

 Paris as a member of the international jury 

 for instruments of precision, it devolved 

 upon Professor Jacoby to present a very 

 brief account of Columbia's research work in 

 astronomy during the past year. The Uni- 

 versity possesses no adequate observatory ^ so 

 that the work in observational astronomy 

 has been perforce confined very largely to 

 the measurement and discussion of celestial 

 photographs. The only long series of direct 

 observations upon the sky itself is that made 

 during the last seven years with the zenith 

 telescope by Professors Eees and Jacoby and 

 Dr. Davis, who was a member of the obser- 

 vatory staff until last year. This series of 

 observations was discontinued in May, 1900, 

 because a similar one, upon a much more ex- 

 tensive scale, has been commenced by the 

 International Geodetic Association. It is 

 hoped that the Columbia observations, to- 

 gether with a corresponding set made at 

 Capodimonte, Italy, will furnish a valuable 

 contribution to our knowledge of the con- 

 stant of aberration and the variations of 

 terrestrial latitude. 



The measurement and discussion of as- 



