Bae a eet Oe i aaah ee ali es | os ania waite Yo | 7 
os PSE AER Se ena LON By er - pepAuneis ao ‘: 
H. A. Hazen— Reduction of Air-pressure to Sea-level. 453 
traced this error to the lagging of the thermometer behind its true 
ling. 
The authors used Geissler thermometers graduated to J;° C.! 
In a series of experiments made by plunging the thermometer into 
: : t 
eause be found in the layer of air around the mercury of the bulb 
which cannot be removed without a reservoir at the top? Or 
may we not also look for such an effect from the minute size of 
the bore of the capillary tube which creates a different pressure 
in the bulb from a rising or falling meniscus? Possibly the two 
may be combined. 
Art. LVL—On the Reduction of Air-pressure to Sea-level, and 
i Determination of Elevations by the Barometer; by H. A. 
s 
years at these stations have been published side by side in the 
