20 
BULLETIN 831, U. S. DEPARTMENT OF AGRICULTURE. 
reasonably Avell founded. The Throop College experiments were 
conducted b}^ Mr. E. X. Allen, a student of the institute, as a basis for 
a thesis, and were directed by Professors Ford and Thomas, also of 
the college, and Mr. Louis C. Hill, of Los Angeles. The Fort Collins 
tests were conducted by the writer, at the cooperative hydraulic 
laboratory of the L T nited States Bureau of Public Eoads and the 
Colorado Experiment Station and, of course, all of these tests 
must be given only such weight as would result from a laboratory 
rather than a working model. They will tend to encourage research 
Fig. 6. — Cross-section outline of Lagolunga Reservoir siphon spillway. This is a typical 
example of the siphons installed in Europe where there is no trash or floating ice to 
clog the throat. 
to develop the proper data from tests in a full-size structure, and 
suggest the study of such points as were not touched upon in the lab- 
oratory tests and will also stand as a guide to the finding of causes 
for the peculiar behavior in the smaller models. Great care was 
exercised in the design of the model siphons to obtain theoretically 
correct proportions for the intake, throat, outlet chamber, and outlet 
opening, both with and without the lower seal. 
In the models for the Throop College experiments corrections 
were made for the friction coefficient of the materials as shown in 
standard tables. The outline of one of the models is shown in figure 
