PUBLIC HEALTH 79 
numbers on and in its cliffs, although the colony is a mere shadow of 
what it was even fifty years ago. Seven species are 
shown nesting in the group—the razor-billed auk, Leach’s 
petrel, gannet, puffin, kittiwake gull, common murre and 
Brunnich’s murre. (Reproduced from studies at Bird Rock, Gulf of 
St. Lawrence.) This was the American Museum’s first habitat group. 
[Return to the South Pavilion containing the apes and monkeys.| 
Bird Rock 
Group 
West CoRRIDOR 
PUBLIC HEALTH 
Returning to the South Pavilion where the monkeys are, and passing 
to the right, we enter the West Corridor containing the exhibits of the 
Department of Public Health. 
The Hall of Public Health is dominated by a bronze bust of Louis 
Pasteur, the founder of scientific bacteriology and preventive medicine, 
which was presented to the Museum through the courtesy of the Pasteur 
Institute of Paris. Near the head of the stairway is a reading table 
where pamphlets bearing on insect-borne disease and other public-health 
problems may be consulted. 
The first section of the exhibit deals with the natural history of water 
supply as it affects the life and health of man. The large 
frieze at the entrance to the corridor on the left illustrates 
the primary source of water supply, the sea, the clouds, and the 
secondary sources, rivers and lakes. Diagrams, models, and a 
relief map show the variations in rainfall at different points in the 
United States. Relief maps of the region about Clinton, Massachusetts, 
before and after the construction of the Wachusett Reservoir for the 
water supply of Boston, show the way in which surface water supplies 
are collected by impounding streams, and a model of a well sunk through 
impervious clay or rock down to water-bearing strata shows how ground- 
water supplies are obtained. A series of samples and models illustrate 
the variation in composition which occur in natural waters, from the 
swamps of Virginia to the deep wells of Iowa and the turbid rivers 
of the Ohio Valley. 
Some of the principal micro-organisms, Algze and Protozoa, which 
grow in reservoirs and impart tastes and odors to water are represented 
by a series of glass models. The effect produced by the pollution of 
water by disease germs is illustrated by relief maps and diagrams show- 
ing the course of famous typhoid and cholera epidemics. Models are 
displayed which illustrate the purification of water by storage, filtra- 
tion, and disinfection, the filter models being elaborate representations 
Water Supply 
