go ; BOTANICAL GAZETTE [FEBRUARY 
The Botanical Department of this University has been par- 
ticularly fortunate in falling heir to two large chambers, the tem- 
perature of which has been remarkably constant during the months 
in which temperature records have been kept. These rooms are 
underground, built of concrete, and were used at one time as tanks 
in which fuel oil was stored. With a change in the means of heat- 
ing our building, these tanks ceased to be used. The site of the 
experiment house, which was built in the summer of 1908, was so » 
selected that these two tanks came under the floor of the green- 
house. The tanks were then cleaned of the residual fuel oil, and 
were ready for use as constant temperature chambers when the 
house over them was completed. Each is entered through a man- 
hole in the floor of the greenhouse, the descent being over an iron 
ladder. Walls, floor, roof, and ladder are of such material that 
they may be washed or hosed off with an antiseptic solution, which 
may then be quickly swabbed up. The air, never excessively dry, 
can easily be maintained at any degree of humidity that one 
chooses, by occasionally sprinkling the walls. The following table 
will indicate the temperatures in one of these tanks during a period 
of nearly five months, these temperatures being taken by a maxi- 
mum-minimum thermometer of the United States Weather Bureau 
pattern.’ They are as follows: 
Date Time Room Maximum Minimum Differences 
PRIN BS) os 4 os oc PE ett a Sede Pao Skea 
March 28 10:00 A.M 16.25 17.22 16.67° 0.55° 
March 29 9:30 A.M 16.2 17.11 16.61 0.50 
PAMRGR 80 oe ek. 16.2 27.11 16.61 0.50 
MAW SUG evinces | ee ss 17.05 16.55 0.50 
fig ig. OR TS RR Rs Coreen: t7, 22 16.55 0.67 
AE Se ee ce eg 17.22 16.50 0.72 
MO ee a 18.89 17.78 1.11 
AAV te ee 18.89 18.05 0.34 
May t6o5i 5 eee oe 18.61 18.05 0.56 
BS ge An Se ee, SN 18.61 18.05 0.56 
May i6... 04. iseo a ee 18.83 18.05 0.78 
MA SN ae 18.77 17.73 0.04 
TS ae Sige ee, Dee pai Olean neal 19.07 17.91 1.06 
August 13 10:30 A.M 20.5 20.55 17.78 ee 
Inspection of this table shows that the lowest maximum was on 
March 31, a temperature of 17.05° C. The lowest minimum was 
3 Bausch & Lomb Optical Co.’s Catalogue, no. 17,004. 
