104 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



D 



ment of turning, cuts off the mercury in the column C 



from that in the bulb A, thereby insur- 

 ing that none but the mercury in the 

 tube can be transferred into the indicating 

 column E. D is an enlargement made at 

 the bend of the tube, so as to enable the 

 mercury to pass quickly from C into E. 

 E is the indicating tube, or thermometer 

 proper, with its scale of degrees. In the 

 E act of turning, as soon as the thermometer 

 is put in motion, and immediately that the 

 tube has acquired a slightly oblique posi- 

 tion, the mercury breaks ofi at the point 

 13, runs into the curved and enlarged por- 

 tion, D, and eventually falls into the tube 

 E, when this tube resumes its original per- 

 pendicular position. "We believe that this 

 thermometer will prove to be of great val- 

 ue on land ; for with it we are at once pro- 

 vided with the means of making observa- 

 tions which will solve some of the most in- 

 teresting questions connected with atmos- 

 pheric temperature. By means of an inex- 

 pensive time-piece,an instrument of thiskind 

 may be made to turn over automatically 

 at any hour that it is desirable, and the record can sub- 

 sequently be read at the observer's convenience. Twenty- 

 four such thermometers, so placed as to be successively 

 inverted at the beginning of each hour of the day, will give 

 us a perfectly definite and reliable hourly record of the tem- 

 perature. London Standard, April 7, 1874 ; and 12 A, 1873, 

 IX., 387. 



\J 



ANEMOMETEY. 



The eminent Cavallero has contributed to the science of 

 anemometry an apparatus for experimental determination of 

 some of the important data wdiich are needed in order to 

 properly use the instruments that have been adopted in meas- 

 uring the velocity of currents of wind, or gases in general. 

 This apparatus has been constructed in the engineering school 

 at Turin, and, according to the description given in the me- 



