22 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



equator can be determined. By this means it can be shown 

 that the land is being lowered by denudation as rapidly as 

 the sea is sinking, and that, consequently, in so far as this 

 part ol'the argument is concerned, it can not be inferred, from 

 the present form of the earth, what its form was at the time 

 when the solidification took place. 12 A, August 24, 323. 



DIFFERENCE IN GRAVITY OF ISLANDS AND CONTINENTS. 



A preliminary report has been made of certain experi- 

 ments that have been prosecuted in India with reference to 

 the determination of the intensity of gravity on an island sta- 

 tion as compared with that of one inland, or on the continent, 

 in the same latitude. As the result of observations upon an 

 island west of Cape Comorin, we are informed that gravity 

 on the coast was found to be greater than inland, and at an 

 ocean station like Minicoy greater than on the coast. 15 A, 

 August 19, 247. 



OZONOMETRY. 



Dr. Moflat stated, at a meeting of the British Association, 

 that ozone test-papers do not become permanently colored in 

 the neighborhood of cesspools, and that the brown colora- 

 tion, when formed, is removed by the products of putrefac- 

 tion. He also said that light, the humidity of the atmos- 

 phere, and the direction of the wind influence the coloring of 

 the test-paper. Moisture with heat accelerates the chemical 

 action, while a strong wind causes a greater amount of ozone 

 to impinge upon the test-paper in a given time. To counter- 

 act the effect of these, he recommends that the test-papers be 

 kept in a box. He described a tube-ozonometer, which he 

 had in use, and gave results obtained by an aspirator ozo- 

 nometer, and concluded by stating that the results obtained 

 by the latter instrument were not satisfactory. 18 A, Aug. 

 25, 562. 



RAltf-PRODUCING DISTURBANCE OF THE ATMOSPHERE. 



Mr. Laughton, of England, examines in Nature the ques- 

 tion whether the condition of the atmosphere can be influ- 

 enced by artificial causes, in the course of which he refers to 

 the assumptions of Professor Espy in regard to producing 

 rain by means of fires, and the oft-repeated assertions that a 



