8 BULLETIN 921, U. S. DEPARTMENT OF AGRICULTURE. 
2. The method employed by the owners of small steam factories 
in regions outside of Louisiana. A number of these factories, scat- 
tered throughout the entire Gulf coastal region from Texas to 
Florida, operate by the general method which the individual farmer 
employs with his small equipment, but use steam power and steam- 
heated coils for evaporating the juice to sirup. They vary in ca- 
pacity from a few hundred to several thousand gallons per day. 
3. The method employed in Louisiana for making sirup. Here, 
too, the power is furnished by steam and evaporation is effected by 
steam-heated coils, but this method differs from the others in that 
lime and the fumes of burning sulphur are added to the juice to 
effect clarification, and, in addition to skimming the heated juice, 
settling tanks are provided in which the material is allowed to settle 
out. The capacities of the Louisiana sirup factories are usually 
much larger than those of the factories in the other States of our 
sirup-producing area. 
Since the farmers employing the first method of sirup making 
operate on a very small scale and with simple equipment, it is hardly 
probable that the method of clarification described in this bulletin 
will be practicable for them. For this reason a comparison will be 
made between this method and the other two methods, where the 
sirup making is conducted on a factory or semi- factory scale. 
For comparison we will consider a plant of 50 tons daily (24 
hours) capacity, operating by the simple method of clarification in- 
volving skimming only. A plant of this type usually has a vat 
fitted with steam coils into which the juice runs direct from the mill. 
Here the juice is heated until the thick blanket of scum which rises 
begins to crack. The heat is then turned off and this blanket of 
scum is removed by skimming. From this clarifying vat the juice 
is run directly to one or more evaporators, where it is immediately 
cooked to sirup, additional scum being removed during the evapora- 
tion. The changes and additions to such a plant for the purpose of 
using infusorial earth clarification would be appreciable, namely — 
(a) Filter presses totaling about 200 square feet in filtering area. 
It is estimated from experimental results obtained with the 18-inch 
filter press that 200 square feet of filtering area will handle the 
juice from 50 tons of cane in 24 hours. In actual experiment, using 
11 pounds of infusorial earth to 1 ton of cane, the juice from 6 tons 
was handled in 4 hours. Suppose, for good measure, that 6 hours 
were required for handling 6 tons with 80 square feet of filtering 
area, then in 24 hours with 80 square feet, 24 tons could be handled, 
and by doubling the filtering area, or with 160 square feet, 48 tons 
could be handled. To make the estimate liberal an additional 40 
