254 ANNUAL RECORD OF S&ENCE AND INDUSTRY. 



highest, that at Yard Station, is 480 feet above the ocean. 

 Kept. If. S. Coast Survey, 1871, 1*75. 



NEW ROUTE BETWEEN AUSTRALIA AND CHINA. 



Captain Moresby has brought to the notice of the Royal 

 Geographical Society a new route between Australia and 

 China, which lies to the west instead of the east of the Lou- 

 isiade Archipelago, and is shorter than the present line of 

 communication by three hundred miles. 13 A, March 0, 

 1875,243. 



PROGRESS OF BAROMETRIC HYPSOMETRT. 



That the investigations of Ruhlmann into the sources of 

 error in the determination of altitudes by means of the ba- 

 rometer has been the beginning of a new epoch in barometric 

 hypsometry is evident from the applause with which his 

 work has been received, and the several attempts that have 

 been made by various meteorologists to carry out the meth- 

 ods of observation recommended by him. 



In this connection we notice the publication, by Mr. Schott 

 and Mr. George Davidson, of a short comparative study of 

 the methods of determining heights by means of leveling, 

 of vertical angles, and of barometric measures. This investi- 

 gation appears to have been begun in 1860, when the obser- 

 vations were first made at two stations about fifty miles north- 

 west of San Francisco ; the field work was only completed 

 in 1872, and consisted of hourly observations from early 

 morning until sunset, with meteorological and geodesic in- 

 struments. The observations have been carefully discussed 

 by Mr. Schott, and he has arrived at the remarkable result 

 that between these upper and lower stations, and during the 

 period over which the observations extend, the temperature 

 of the intervening stratum of air was nearly constant through- 

 out the entire day. There seems, in fact, no trace of a daily 

 variation, as though the rays of the sun passed through the 

 air without sensibly heating it. For this location, therefore, 

 we must conclude that the daily variation of temperature 

 shown by ordinary thermometric readings belongs mainly to 

 the layer of air in contact with or in close proximity to the 

 earth's surface. The computed altitude of the upper station 

 above the lower one, as compared with the true altitude de- 



