Aug. 19, 1918 
Influence of Humidity on Wool Fiber 
293 
on both sides, and the ceiling and floor of reinforced concrete. In one 
side there is a large, well weather-stripped window, the upper part of 
which has an opening 7 inches wide and extending the entire width of 
the window. This opening was designed for ventilation purposes, but 
was found inefficient and was displaced by artificial ventilation. The 
entrance to the room is provided with double doors separated from 
each other by a small vestibule, so that one can enter this vestibule 
and close the door before entering the humidity room. The joints of 
these doors are well weather-striooed. A corner of the room is shown 
in Plate 48, A. 
The temperature of the room is controlled by a thermograph con¬ 
nected through a pony relay to a bank of lamps fastened overhead and 
covering an area of about 6 square feet. The lamps remain lighted 
until the arm of the thermograph records the desired temperature. At 
this point the indicator of the thermograph makes a contact with a 
small adjustable platinum arm, thereby closing the circuit from a bell¬ 
ringing transformer, which in turn actuates the relay magnet and breaks 
the light circuit. There is a large tank in the upper part of the room 
which may be filled with running water and used as a cooler to keep 
the temperature of the room from going above that desired. At this 
station, however, it is not ordinarily necessary to use the cooler, as the 
main laboratory can easily be kept below 70° F., the temperature at 
which the fiber-testing machine is most used. 
The humidity of the room is controlled by an electrical connection 
through a hydrograph indicator similar to that through the thermograph. 
When the humidity of the room reaches the desired percentage, as 
recorded on the hydrograph, the circuit through a ^ h. p. motor which 
works an atomizer above the tank in the upper part of the room is au¬ 
tomatically broken. By means of reducing gears and a crank arm, this 
motor operates two small air compressers of the bicycle foot-pump type. 
The two pumps are placed in a horizontal position with their piston rods 
connected to each other and are also connected through a jointed arm, to 
the crank pin so that each half turn of the crank causes a forward stroke 
of one piston and a backward stroke of the other. The air from each 
pump is conducted to an atomizer in the top of the room. These atomizers 
are of the household type, but have been modified to fit i-gallon glass 
jugs. The greater part of the spray from these atomizers settles into the 
large water tank, any spray reaching the center of the room being so fine 
that it is practically all absorbed by the atmosphere before it reaches the 
floor. The method of pumping is entirely improvised and could easily 
be replaced by a small electric blower. 
Both the thermograph and hydrograph can be quickly set for a new 
temperature or humidity. The temperature can be regulated with ease 
at any temperature between 65° and 8o° F. and the humidity anywhere 
