INTERESTING SCIENTIFIC WORK IN THE ARCTIC 215 



temperature recorded. In the Arctics naturally a set of the latter 

 instruments relieve the explorer, as the reading may be taken at 

 any time for the lowest or highest point reached since the 

 last setting of the instrument. 



Continuous recording thermometers, which give an hourly 

 record in ink upon a paper cylinder, are 

 far too delicate for the rough handling 

 of a sledging trip, and consequently are 

 not carried. 



A full equipment of scientific instru- 

 ments might also include a wind gauge 

 or Anemometer and deep-sea sounding 

 instruments. 



The Anemometer consists of a small 

 fan, upon which the wind acts. The 

 revolutions of this fan are recorded by a 

 series of dials, which indicate the veloc- 

 ity of the wind in feet per minute. 



For deep-sea sounding, a sounding 

 machine is used which automatically 

 records the pressure of the water, and 



from this the depth may be ascertained, as the two are in exact 

 proportion. 



The well-known compass completes the explorer's outfit of in- 

 struments, but, as has been explained, it is of little use in the 

 high latitudes near the North Pole, because it points, not to the 

 actual North Pole, but to the Magnetic North Pole, a point far 

 distant. 



ANEMOMETER. 



Instrument ty Queen & Co., 

 Philadelphia. 



