PRODUCTION OF SIRUP FROM SWEET POTATOES. 
The agitator was driven by 
means of a beveled pinion and 
gear, ratio 1 to 4, giving the 
agitator a speed of 18 revolu- 
tions per minute. Aside from 
the large starting torque re- 
quired, this arrangement gave 
satisfactory service. The po- 
tatoes could be broken into a 
mash within 8 or 10 minutes. 
A quick opening, 3-inch 
valve, fastened to the side of 
the tank near the bottom, 
made it possible to draw off 
the heavy maslj rapidly. The 
tank was fitted with a galva- 
nized-iron cover with hinged 
doors on either side. 
HYDRAULIC PRESS. 
Fig. 5. — Mash tank (cross section). 
The hydraulic press (Fig. 
6) used to press the wort from 
the pomace was of the type employed in the manufacture of grape 
juice. As originally designed, the press called for the use of 28-inch 
racks. To meet the demands at Fitzgerald, the pressing area was 
enlarged to handle racks 48 by 36 inches. With this arrange- 
ment, the mash from a 50-bushel batch could be pressed in three 
hours. 
A truck ran on a track from the press to the mash tank. After 
being loaded with layers of pulp and racks the truck was pushed 
to the press, where the plunger lifted it against the pressure head, 
forcing the wort from the pomace. The wort drained into a gal- 
vanized-iron catch tank, 6 by 3 feet by 1 foot deep, which was set 
in between the tracks. , 
From the catch tank the wort was pumped to an overhead tank, 
or reservoir, from which it could be drawn as desired into the evapo- 
rator. 
EVAPORATOR. 
A horizontal, continuous open-type evaporator made of maple 
(Fig. 7) was used in concentrating the wort into sirup. It was 15 
feet 8 inches long by 30 inches wide by 12 inches deep. A bailie 
wall extended from one end down through the middle of the evapo- 
rator to within 16 inches of the other end. The inside of the evapo- 
rator was lined with 24-gauge galvanized iron. Heat was furnished 
by two sets of three-fourths-inch copper coils of three pipes each, 
placed side by side on the bottom of the evaporator. The evaporator 
required 40 boiler horsepower at 80 pounds gauge pressure. This 
corresponds to approximately 1,200 pounds of water evaporated per 
hour. The coils were so installed in the evaporator that the incom- 
ing sirup could be heated by the exhaust end of the coils. As the 
sirup became more concentrated it was heated by hotter steam. In 
37996°— 23 2 
