210 
THE METHODS OF WIND MEASUREMENT. 
blowing from different quarters on the same day. Yet a series 
of records obtained simultaneously from integrating anemometers 
at different points would be exceedingly interesting, and it is 
hoped that a Government grant may be obtained for the 
construction of a more perfect instrument. It is to be observed 
that the marks at equal intervals of time along the curve would 
enable the velocity to be determined, and might be graphically 
exhibited at every point by the width of a figure constructed 
along the curve. 
The location of the anemometer as well as its construction 
is a very important matter, not only as regards the nature of the 
surrounding country, but also as regards its position with respect 
to the building or structure on which it is placed. Both the 
points have latterly received more attention than apparently 
used to be the case. That an anemometer should not be placed 
on a high building with vertical walls is generally acknowledged : 
the one at Kew, for instance, being supported on a framework 
above the dome of the observatory. A series of experiments 
have been made by Mr. F. Stevenson (Scottish Meteorological 
Society) with a view of determining the height above the ground 
at which an anemometer should he placed to record the real 
velocity of the wind, which he concludes should be a minimum of 
50 feet, and where this is not possible the velocity V at the 
height H should be computed from the observed velocity at the 
height h {Ji not being less than 15 feet) by the formula 
and it would be obviously desirable thus to refer all velocities to 
some fixed height above the ground. 
The foregoing are the principal methods employed in ane- 
mometry, but only a small number of the instruments 
suggested, or constructed, even in this country, have been 
mentioned, and a glance at the text book of Weisbach, or the 
