45, CORNHILL, E.G., AND 122, EBGENT STREET, W., LONDON. 95 



APPARATUS EMPLOYED FOR REGISTERING THE DIRECTION, PRESSURE, AND 



VELOCITY OF THE WIND- 



FIG. 107. 



THE records obtained by the use of various forms of Anemometers are equally 

 interesting and valuable. 



The amount of pressure and velocity of the wind are now registered 

 with such precision, that it enables Millwrights and Engineers to make their 

 calculations and arrange their machinery in accordance with the amount of 

 work required to be done, and also to test and compare the expected with the 

 actual results. 



Meteorologists are equally interested in Anemometer records. The points 

 of direction and the duration of the wind in particular quarters and seasons 

 have very much to do with the Rainfall and Evaporation in different countries 

 and localities. The late Admiral FitzRoy in his Weather Manual repeatedly 

 indicates the great importance of careful observations on the various phenomena 

 of the wind in connection with Marine and Sea Coast Meteorology. 



134. Wind Vane, for indicating the direction of the wind. See next page. 

 It is important to note that the North point of the Vane should be 



carefully adjusted to the Geographical or true North, and not to the Magnetic 

 North. See Compass Variations in Appendix at the end df the volume. 



135. Anemoscope. Dr. Halleur's Portable Wind Vane and Magnetic 

 Compass, for showing the direction of the wind to half a point of the compass. 

 This instrument is very similar in form and size to Lind's Wind Guage, shown 

 on page 98. Fig 109. Price 250 



