B. TEREESTRIAL PHYSICS AND METEOROLOGY. 93 



gas at 800 meters' altitude, 24 parts out of 100,000; and at 

 1000 meters, 30 parts out of 100,000. The difference between 

 the two figures is the limit of the errors of observation. 13 

 B., III., 333. 



EARTHQUAKE IX THE VICINITY OF NEW YOEK, DECEMBER 



10, 1874. 



On the 10th of December, 1874, an earthquake was felt in 

 the neighborhood of New York, especially near Yonkers. It 

 has formed the subject of study by the New York Lyceum of 

 Natural History. From a report made to the Lyceum by Pro- 

 fessor D. S. Martin, it appears that exact observations could 

 not be obtained sufficient to give a definite basis for any 

 physical investigation; showing, we may remark, forcibly, 

 as is shown in a thousand other ways, the importance of hav- 

 ing a uniform standard time, which shall replace the innu- 

 merable erroneous local times adopted in every portion of our 

 country. Had each of Professor Martin's observers possess- 

 ed a time-keeper set to correct time, he would have been able 

 to add much of interest to our knowledge of the nature of 

 this earthquake. In general, he states that the shock was 

 felt from near Fishkill, southward, eighty miles, to Sandy 

 Hook, and in an east and west direction from Morristown, 

 New Jersey, eastward, sixty miles, to Stamford, Connecticut. 

 The movement was felt far more strongly and frequently on 

 rocky than on soft ground. In the main, the shocks seem to 

 have been limited by the Highlands of New York and New 

 Jersey. In only one case was the shock reported as felt on 

 the water, which was by a schooner in the harbor of New 

 Rochelle. 



VOLCANOES IN ICELAND AND ASH-SHOWERS IN NORW r AY. 



A series of interesting volcanic phenomena has been, for 

 some time past, in progress in Iceland, outbreaks having 

 occurred from January to April. The eruption was steadily 

 spreading over the wilderness, and so large a district of the 

 surrounding country has been covered with ashes that the 

 farmers have been obliged to remove, in order to find past- 

 ure for their stock. The eruption from the principal crater 

 takes place through a fissure, from which the molten red-hot 

 lava is thrown two or three hundred feet into the air, in one 



