A. MATHEMATICS AND ASTRONOMY. 29 



were largely connected with spectroscopic observations, and 

 these were successful in a very high degree. The solar prom- 

 inences and chromosphere were seen far more clearly than 

 ever before, and Secchi's "layer of continuous spectrum at the 

 sun's limb" was repeatedly verified. There were observed in 

 the spectrum of the chromosphere 165 new, bright lines, mak- 

 ing the total number known 268. Of the 103 previously re- 

 corded, all but 30 had been catalogued at Dartmouth. . 



The most interesting observation of all, however, was the 

 discovery of the permanent reversal of the H lines of the spec- 

 trum of the chromosphere, and the fact that the same lines 

 are reversed on the surface of the sun itself over quite a large 

 region surrounding every spot. It is thought improbable 

 that these observations can be verified by instruments near 

 the sea-level. College Courant, October 5,1872,153. 



PROCTOR ON PHYSICAL OBSERVATORIES. 



Mr. Richard A. Proctor, in an article on National Observa- 

 tories for the Study of the Physics of Astronomy, refers to 

 the communication of Colonel Strange, made to the British 

 Association last year, urging the propriety on the part of the 

 government of establishing observatories for the study of the 

 aspect and changes of aspect of the sun, moon, and planets, 

 on the ground that the establishments already in operation 

 confine themselves too much to determining the position and 

 motions, real or apparent, of the celestial bodies. 



Colonel Strange, in urging his project, calls attention to the 

 great uncertainty that has hitherto prevailed in regard to 

 climatological laws, and promises that, if observatories are es- 

 tablished especially for the purpose, there is a strong proba- 

 bility that the systematic study of the sun will throw useful 

 light upon climatological conditions. To this Mr. Proctor re- 

 joins that, while all weather changes may be traced to the 

 sun's influence, the idea that we shall ever be able, by study- 

 ing the spots, the facula?, the prominences, or the chromato- 

 sphere of the sun, to interpret the phenomena of the weather, 

 appears demonstrably incorrect. While the sun's diurnal 

 course accounts for the seasonal changes, we yet know that 

 the weather of any single day is almost wholly independent 

 of the general character due to the season. A season may be 

 exceptionally cold or hot in one portion of the earth, while 



