ATR OF NEW YORK SUBWAY—SOPER. 653 
rapid changes of the latter. This correspondence is seen to be most 
marked when the data for inside and outside are compared in the 
form of weekly and monthly averages. (See fig. 2.) 
The temperature in the subway for the daytime for July and 
August, combining the records of these two months to form an aver- 
age, was 82.4°; it was 76.8° outside; difference, 5.6°. 
Highest temperatures in the summer of 1905.—The highest tem- 
perature observed in the subway during the investigation was 95°. 
This occurred at the Brooklyn Bridge station, July 18, 1905, at 
3.50 p. m. 
The hottest week was that of August 4 to 10, inclusive. The aver- 
age daily temperature for the subway during this time was 83.4°; 
for the outside air, 78.2°; difference, 5.2°. 
Fig. 2.—Weekly average temperatures in the subway and streets from July 10 to 
November 13, 1905. These averages are made up of 47,476 observations. 
The maximum temperature observed in the subway during this 
hottest week was 88.2°; in the streets it was 88.2° at the same time. 
The express stations, with the exception of Ninety-sixth street, 
which was exceptionally open to the outside atmosphere, were all 
warmer than the local stations in their vicinity. 
The coolest stations were those which were most open to the street; 
the hottest the most closed. 
The relative humidity in the subway was generally less than that 
out of doors, but the temperature of the dew point was higher. In 
other words, the actual weight of aqueous vapor present was greater 
in the subway than outside, but it appeared to be less in the subway 
than in the streets. 
The humidity in the subway varied with the humidity out of doors. 
(See fig. 3.) 
There were no fogs nor mists in the subway. A faint haze was 
not uncommon. 
