6 BULLETIN 1465, U. S. DEPARTMENT OF AGRICULTURE 
glass panes of two small side windows were sealed in. Before the 
door was a small platform. Two small half-round tracks ran through 
the center of the room and to the edge of the platform. A small 
carriage with a swivel top was pushed back and forth along this track. 
The carriage could be pushed outside of the door, a can deposited 
on it, the whole pushed inside, and the can rotated as desired. 
On each side of the interior were shelves extending the entire length. 
They were made of thin strips of wood turned edgewise with spaces 
between. This gave sufficient strength, but allowed water to fall 
through. Directly overhead was a water sprinkler of the type used 
in protective systems. The operator, after entering the building 
with all necessary apparatus, closed the door and turned on the 
sprinkler, wetting down the walls and precipiting all dust. By stand- 
ing beneath the sprinkler the operator escaped a wetting. The cul- 
ture house and the boiler house are shown in Plate 2, B. 
THE WEIGHING FRAME AND BALANCE 
The cans were weighed frequently to determine the water loss. 
The frame devised by Briggs and Shantz 2 was used for this purpose. 
It consisted of four upright pipe posts 8 feet high forming a frame 
2J^ feet square. At the top, between the midpoints of two connect- 
ing pipes, was a shaft with a small gear at the end. An endless chain 
dropped down to one post, where at a convenient height was a simi- 
lar gear turned by a hand crank. At the bottom of the two pairs of 
posts between which the overhead shaft extended were two wooden 
skids to which the frame was fastened and on which it was moved 
about. 
From the shaft above a short rope loop was dropped, in the sag 
of which hung a small pulley and hook. By turning the crank the 
rope was wound around the shaft and the pulley and hook were raised. 
The endless-chain arrangement was greatly improved by placing a 
sprocket wheel of large size midway between the two gears and be- 
tween the vertical parts of the chain. The sprocket wheel merely 
rotated in place when the crank was turned, kept the chain taut, 
and prevented it from slipping and doing damage to the balance. 
The balance was of special design, of the spring-balance type. In- 
stead of recording from zero to capacity, it began at 50 kilograms. 
This permitted the use of a more positive spring, better adapted to 
the heavy weights and the rough usage it received. The 12-inch dial 
was graduated to half kilograms. At the end of the indicator was 
a 5 point vernier which permitted the scale to be read easily to 100 
grams. 
THE WATERING MACHINE 
It was necessary to supply the cans with water in order to replace 
that lost by evaporation and transpiration. The water needed to 
be supplied in quantity, in a sterile state, and under aseptic condi- 
tions. Contamination of the cans might easily have been brought 
about by an impure water supply, carelessly handled. 
To meet this need a machine was devised in which water in quan- 
tity could be sterilized and dispensed as needed. It consisted essen- 
' See literature cited in footnote 1. 
