‘ 
GENERAL MEETING. 47 
Dry ther- Wet ther- Relative humidity ; 
mometer. mometer. per cent. 
Russian. Pattern. R. BE: I P 
StU alr See ACTS isha 64°.0 62°.7 52.4 S10 
Light south wind-_ 77 .2 “Wien 62.0 61.0 3087) 134.5 
These results show directly the advantage of a good circulation 
of air, and that after shielding from the sun and radiation to the 
sky with a shelter at least 3 feet long, we may neglect other consid- 
erations. 
Experiments are still in progress to determine the proper height 
above sod or roof, the proper exposure for a north window, and so 
forth. 
Mr. ANTISELL, referring to the general theme rather than to 
the special subject of the paper, took occasion to note that the 
practice of conducting meteorologic observations on the tops of 
highshouses, while it may well subserve the special purposes of the 
Signal Service, renders their work of materially less value to the 
medical profession. There is so much change, especially of the 
moisture element, in the first few feet from the ground upward that 
no observations can be depended upon as reporting the conditions 
of the phenomena of disease unless they are made in the layer 
actually occupied by man. 
Mr. Taytor asked whether there might not be an error arising 
from the set given to the glass of the bulb by the pressure of the 
mercury of a whirled thermometer. 
Mr. HazeEN replied that he had tested the effect of pressure ap- 
plied to the bulb with the finger, and found that the set produced 
was of very brief duration. He had also tested the thermic effect 
of the friction on the atmosphere incurred by rapid whirling, and 
found it inappreciable with a velocity of about fourteen miles an 
hour. On whirling a black bulb thermometer, he observed a change 
of several tenths of a degree, which appeared clearly referable to 
the greater coefficient of friction of the surface roughened by lamp- 
black. 
Mr. Granam BExt remarked that if we eliminate radiation and 
learn the absolute temperature of the air at the point of observa- 
tion, our knowledge is still limited to that point only, whereas for 
meteorologic purposes it is important to ascertain the average tem- 
perature of a body of air. He suggested the possibility of utilizing 
for this purpose a measurement of the velocity of sound, which 
