A. MATHEMATICS AND ASTRONOMY. 23 



shaped body, surrounded by a blue light, and which approach- 

 ed the earth at an angle of thirty to thirty-five degrees with 

 great velocity, leaving behind it a train of vapor. 



One of the observers affirmed that this red body continually 

 emitted incandescent particles, and separated into two parts 

 in its course, and that the two globes of fire fell separately 

 upon the earth. The phenomenon is said to have lasted four 

 or five minutes, while the smoke emitted by the bolid re- 

 mained visible for ten minutes afterward. Some persons 

 even professed that they perceived a decided smell of burn- 

 ing sulphur; and one of those who picked up a fragment a 

 little time after its fall said that it was not free from the 

 odor for three days after. 



The number of stones that fell on this occasion was quite 

 considerable, two of them being much larger than others, one 

 weighing nearly 600 pounds, and the other about 80 pounds. 

 At least a thousand fragments were picked up, being scat- 

 tered over a surface of about 6600 feet in length by 2500 in 

 width. The largest mass penetrated the earth to a depth of 

 eleven feet, and the smaller to that of about two feet. 1 E^ 

 1872,XII.,11,146. 



DIFFERENCE IN LONGITUDE BETWEEN CAMBRIDGE AND 



SAN FRANCISCO. 



As the result of a series of observations, carefully conduct- 

 ed by Mr. Deane, of the Coast Survey, and his associates, it 

 lias recently been established that the difference in longitude 

 between Cambridge and San Francisco amounts to 3 hours, 

 25 minutes, 1 seconds, and a small fraction. 4 Z>, December 

 1871,448. 



MASKELYNE ON METEORITES. 



Mr. Maskelyne, the chief of the mineralogical department 

 of the British Museum, in a recent lecture before the Royal 

 Institution, gave an account of the present state of our knowl- 

 edge of meteorites. According to the lecturer, the maximum 

 height at which these have been observed is 120 miles, and 

 their velocity from 18 to 34 miles a second, this resulting in 

 great heat, intense light, and violent explosive force. The 

 heat, he thinks, is due to the retardation of the velocity by 

 passing from a rarer medium to our denser atmosphere. He 



