METEOROLOGICAL OBSERVATIONS AT CARNWATH. 257 



XXX. Report on the Mcleoroloyical Observations made at Carn- 

 ivath, Lanarkshire, in connection with the influence of Forests 

 on Climate. By Alexander Buchan, M.A., F.R.S.E., 

 Secretary of the Scottish Meteorological Society. 



In the Report of the Committee submitted to the Annual 

 General Meeting on 1st November 1876,* it was proposed to 

 remove the Louvre-boarded box with the thermometers from the 

 station outside the wood at Gallowhill to a new position inside 

 the wood, where the thermometers would be completely shaded by 

 the trees, but at the same time in as close proximity as possible to 

 the station inside the wood, at which the thermometer box is 

 fully open to the influence of solar and terrestrial radiation ; and 

 to add at each of the two stations a set of underground thermo- 

 meters at depths of 3, 12, and 22 inches, to be observed daily 

 with the other instruments. 



The object kept in view in making these changes and additions 

 was to determine whether there might not be a very considerable 

 difference in the mean temperature of the air and of the ground 

 at two stations in the same wood within a very short distance of 

 each other, and under precisely the same conditions, as regards 

 height above the ground and the sea, slope of surface, etc., but 

 differing in the important particular, that while the one station is 

 completely shaded by the trees from direct solar and terrestrial 

 radiation, the other station is open to these influences, and the 

 instruments placed over grass just as in the case of ordinary 

 observing meteorological stations. 



Two sets of underground thermometers were accordingly pro- 

 cured, compared, and got ready by the end of the year; but it 

 was impossible to cany out the arrangements at Carnwath till 

 8th March. Since a short time before my visit to Carnwath on 

 that day, the trees had been cut down in considerable quantities 

 immediately all round the old station of Winterlaw in the heart 

 of the wood, and the thermometer box thereby exposed fully to 

 the sun for nearly the whole day, no shadows from the trees 

 falling on it, it was resolved to adopt simpliciter the Winterlaw 

 station, as now altered by the cutting down of the trees, as one of 

 the two new stations, seeing that it entirely fulfilled the required 

 conditions. Immediately adjoining this fine plot of grassy sward, 



* Vol. viii., p. 169. 

 VOL. VIII., PART III. S 



