138 MESSRS. M". N. SHAM" AND M'. H. DINES; METEOROLOGICAL OBSERVATIONS 
country for tlie reduction of average temperatures at a network of stations to a 
common level. They are much below the results of the kite ascents at 17 stations in 
the United States, obtained by the ^'feather Bureau, hut they agree very closely 
with the results of the Berlin balloon ascents. With regard to these last, however, 
a higher figure should be taken for the lowest stage of 500 metres for day ascents in 
the summer. 
All these differences may probably he satisfactorily accounted for by the circum¬ 
stances of the Crinan ascents, which were over the sea on the edge of the Atlantic, 
where the daily range of temperature is almost negligible. At greater heights the 
Ch’inan results are substantially lower than the Berlin results and the adiabatic 
gradient, but the number of high ascents is very small, and, as already stated, they 
refer to a particular tyjDe of summer weather which is probably different from those 
of the balloon ascents. 
The average gradient for Ben Nevis—Fort William for the corresponding months, 
•7 0°, is considerably higher than the Crinan gradient for the same height. The actual 
differences between the temperature at the sea level at Crinan and the top of Ben 
Nevis, on the days when the Ben Nevis temperature was reached by the kites, as 
shown in Table A, vary between 13° on August 25 and 5° on July 7, the average 
being 9'3°. The height in the free atmosphere, at which the Ben Nevis temjDeratures 
were reached ])y the instinment, is shown by the cross marks on the Diagram 
(Plate 12). 
The differences of temperature Ijetween the summit of Ben Nevis and the free air 
at the same level over the sea near' Crinan, as determined bj^ the kite experiments, are 
shown in the following table (Table C). The same table gives also the wind direction 
and force, and the wet and dry bulb readings for tlie mountain and for Fort William. 
