SUPPLEMENTARY REPORT ON METEOROLOGY. 103 
which, especially in their connexion with moisture, have a most 
important influence on climate. 
196. All these phenomena deserve a more careful examination 
than they have received, with a philosophical view of referring 
them to their common cause. What has been done in this way 
we will presently notice. But first, we will say something as 
to means of investigation. 
A. Anemometers. 
197. In my former report I remarked, that if anything were to 
be done in the way of anemometrical observations, it must be by 
the use of self-registering instruments. Two such have been 
invented, and pretty extensively used in this country. 
198. Mr. Whewell* has described an anemometer proceeding 
on the ingenious principle, that the meteorological importance 
of a wind blowing in a given direction is not to be estimated by 
the number of days or hours that it blows in a given direction, 
but by the compound ratio of the time and force. This he 
endeavours to obtain by causing a pencil to describe a vertical 
line with a velocity proportional to the number of turns of a 
vane with which it is connected, whilst at the same time the 
pencil is carried round a cylindric surface by an apparatus like 
that which guides a windmill, so as to point out the azimuth of 
the wind. The length of line described by the pencil between 
two given azimuths shows the integral effect of force and time 
for that interval. The instrument has been worked with very 
considerable success at Cambridge, under the directions of 
Professors Whewell end Challist, at Plymouth by Mr. South- 
wood{, at Edinburgh by Mr. Rankine§ and myself, and in 
other places. From its construction (friction being the anta- 
gonist force or regulator), perfect comparability cannot be ex- 
pected. 
199. Mr. Osler, of Birmingham, has invented and constructed 
an ingenious but complicated apparatus for measuring the force 
and direction of the wind at any moment, and for keeping a re- 
gister of these particulars in the absence of the observer||. It 
consists of a very powerful vane, which carries round the stalk 
to which it is affixed ; this stalk terminating in a pinion, moves 
a rack connected with a pencil, which describes upon paper the 
* Cambridge Transactions, vol. vi. part ii. 
+ British Association, 7th Report, Sections, p. 32, and Camb. Transactions. 
t Ibid., 8th Report, p. 28. § Edin. Trans. xiv. 359. 
|| British Association, 7th Report, Sections, p. 33, and “ Description of a 
Self-Registering Anemometer and Rain-Gauge.” 4to.. Birmingham, 1839, 
with a plate. Some parts of the apparatus have been more lately modified. 
