4 
BULLETIX 494, U. S. DEPAETMEXT OF AGEICULTUEE. 
water, and in this condition the water was drawn into the cloths by 
capillarity almost to the top of the frames. Over the frames was 
placed a galvanized-steel cover, or hood, open at one end and so ar- 
ranged at the other end as to inclose a 16 -inch electric fan. The cur- 
rent of air from the fan was directed between and over the saturated 
cloths. In this way the water was evaporated and given off to the 
air in the room, increasing the relative humidity more efficiently 
and safely than by any method previously tried. However, it was 
soon found that the upper part of the cloths soon became dry under 
the influence of the air current from the fan, and in an hour or so 
the effectiveness of the apparatus became greatly diminished. 
An attempt was then made to find a cloth more absorptive than 
the kinds first used. Many materials were tried, with the result 
that it was decided to use Russian crash, a very coarse linen cloth 
that is used for making towels and for decorative purposes. 
With the use of the Eussian crash cloths the efficiency of the 
humidifier was improved, but it was still imperfect under very dry 
atmospheric conditions. Various expedients were tried to increase 
still further the evaporation of the water in the pan, such as by the 
addition of filter paper, sponges, and other quickly absorptive 
materials. 
THE INVENTION OF THE HUMIDIFIER. 
While working on this phase of the problem, the writer con- 
structed a machine with two water pans, an upper and a lower one, 
with strips of cloth extending through slots in the bottom of the 
upper pan to the lower pan. It was thought that in this machine it 
would be possible to control the flow of water from the upper pan 
to the cloths through the slots by pressing the slots together by means 
of thumbscrews. This method was found to be impracticable. It 
was in this work that the idea occurred of raising the sides of the 
slots several inches, so that they protruded above the water in the 
top pan. The cloths were drawn up through the raised slots and the 
edges were allowed to drop into the Avater to the bottom of the pan. 
Under these conditions, the water in the pan was raised on the- 
cloths by capillarity to the top of the raised slots, where it dropped 
down through the suspended cloths by gravity and capillarity com- 
bined. This arrangement proved to be successful in every respect 
and met the requirements for use in lemon curing rooms very 
satisfactorily. 
It was found that the rate of flow of water from the upper pan 
through the cloths to the lower pan could be regulated to a nicety 
by var^dng the height of the raised slots, thereby changing the length 
of the cloth through which the water is drawn b}^ capillarity. 
