34 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



cold arctic current meets the warmer waters of the Gulf 

 Stream, and that they are not West Indian hurricanes cross- 

 ing the Atlantic from shore to shore. 1G A, April, 1871, 282. 



STORM-SIGNAL STATION IN THE AZORES. 



Dr. Buys Ballot, the eminent director of the Meteorological 

 Observatory of Utrecht, has been lately urging the Portu- 

 guese government to establish a station in the Azores, to be 

 connected with the general system of European meteorolog- 

 ical observatories by a submarine cable which will shortly be 

 laid in that direction. By the reports of southwestern gales 

 that can be obtained in this way, it is expected that an am- 

 ple premonition of their approach can be given to the British 

 Islands and Western Europe? This will greatly improve the 

 system of weather forecasts as now attempted in Europe, 

 and make them approach more nearly in accuracy to those 

 of the United States Signal Corps, which have astonished ev- 

 ery one by their reliable indications. This accuracy is due 

 to the fact that most changes in the weather begin in the 

 west and extend eastward ; and the greater the distance to 

 the westward over which such observations can be made, the 

 more time will be given, of course, toward the east to pre- 

 pare for the impending changes. 12 A, June 22, 1871,156. 



DETERMINATION OF HEIGHTS BY THE BAROMETER. 



Professor J. D.Whitney, in a recent communication to the 

 Academy of Sciences of San Francisco upon the use of the 

 barometer in determining altitudes, remarked upon the effect 

 which temperature exerts upon the instrument, and stated 

 that the difference between the cold of winter and the heat 

 of summer would sometimes, in the same instrument, involve 

 a difference in the cstimato of a given height of as much as 

 seventeen feet. lie hoped in time to have tables prepared 

 which should give the allowances that must be made for each 

 day of the year, and for different times in the day, an obser- 

 vation at 9 AM, sometimes giving a different result from one 

 taken at 2 P,M. at the same altitude on the same day. He 

 also expressed his dissatisfaction with the aneroid barometer 

 as a means of measuring altitudes, although he had experi- 

 mented with the best that were offered in the market. He 

 found them reliable for a certain time only, and they appeared 



