REPORT OF THE SECRETARY. LS 
physical properties of carbon of the remarkable absorption of gases 
at low temperatures is to be investigated, and two methods of deter- 
mining the specific heat of gases have been perfected. The investiga- 
tion of the properties of matter at the temperature of liquid hydrogen 
will also be continued and the results recorded. 
STUDY OF THE UPPER ATMOSPHERE. 
The meteorological experiments of Mr. A. Lawrence Rotch with 
registering balloons, conducted from St. Louis as the starting point, 
have been again aided by a grant from the Hodgkins fund. Before 
the close of similar experiments by Mr. Rotch from the same point 
in 1906, the extreme height of nearly 10 miles was attained, and a 
temperature of —76° F. was once recorded somewhat below 7 miles. 
This final series of ascensions aided by the Institution is intended 
to supply data for the season of the year in which observations of 
the upper air have heretofore been the least frequent, and it is hoped 
that the endeavor to ascertain the annual variation of temperature 
at great heights in the free air above the American continent will 
thus be materially furthered. 
A summary of the results of the meteorological research conducted 
by Mr. S. P. Fergusson, mentioned in the previous Report as having 
been aided by a moderate grant from the Hodgkins fund of the 
Institution, has been submitted. 
Stations for these experiments were established on the summit of 
Mount Washington, 1,916 meters above sea level, and at Twin 
Mountain, 1,500 meters lower and 15 miles distant. Louvred shelters 
were built for the proper exposure and protection of the instruments 
at these stations, and the anemometer was erected on the old Tip Top 
House, the highest point on the summit of Mount Washington. 
Records were made at the stations, as nearly as possible continuous, 
of pressure, temperature, humidity, and wind velocity, while the 
meteorographs recording the same elements were sustained by kites 
in the free air for as long a time as possible during the research. 
Observations of the formation of clouds on the mountain and in the 
free air were also made. 
While the apparatus used in this research was the same in principle 
as that heretofore employed, it is hoped that certain devices which 
were suggested by the conditions, and successfully adopted, will 
prove advantagegus in later experiments. The time available for 
this research was necessarily limited, but the kites on several different 
occasions carried the meteorograph sufficiently high for comparison 
with the records obtained on Mount Washington. On the 6th of 
September the instrument was kept at approximately the same height 
in the free air and on the summit of Mount Washington for eight 
hours between noon and 10 o’clock p. m. 
