The Birmingham age-herald., 1909-04-29
NOVEL TESTS MADE
 ON EVAPORATION
Tubs At East Lake Are Attract
 ing Attention
HOW THE WORK IS DONE
Tennessee Company Planning for Big Reservoir and Wanted Exact Fig ures on Amount of Evapora-
 ton at Various Attitudes.

The constant work of improvement carried on by the large industrial con- cerns of the Birmingham district is il lustrated by the evaporation tests under way at the Shades valley reservoir and East Lake by the Tennessee company under the supervision of the United States government.
 This work has been under way for sev- eral months, and it will probably be next November before it is completed. It is being done directly under the supervision of William F. Lehman, the local weather observer, while the actual work is being done by assistants in the employ of the Tennessee company. The government Is furnishing the necessary instruments.
 Tests at the reservoir on Shades noun tain have been about completed, while the East Lake tests are well under way. The manner in which they are made Is simple, but requires watchful eyes.
 Galvanized Iron tubs are placed at six different points on and around the lake. These tubs are then partially filled with water. An ordinary stick file Is set in the center of the tub with the point pass
 
 pot. The tub is filled so that the surface of the water is even with the point of the file. Each tub is visited six times a day and notes made of the amount of water evaporated
 In order to ascertain the exact amount of water evaporated a glass graduate carefully gauged Is used to fill the tub with sufficient water to make 1t level with the point of the file, the quantity of water required to do this representing the evaporation taking place since the prev ious visits.
 Tests are being made at different levels. One tub is floating in the middle of the lake, while another Is on a platform 10 feet above. At one end of the lake there is another tub floating and a wind gauge on a platform 10 feet above.
 The "shoot the chutes" was also seized upon as a good place for placing the tubs. three being placed on the frame work at different levels, the highest being 50 feet
 Two young men, Eugene M. Lokey and w. s. Sanders, are engaged on this work. which keeps them pretty busy. There are 36 tests each day.
 There have been but few of these evap- oratlon tests made in America, and these were made during the past year or two, At present there are but four stations for this east of the Mississippi river and one in the west.
 The Tennessee company is planning to build a water works system to supply It's own needs and they are making this test i,,O Orda thaNr 2 fllll nnder- standing of the conditions confronting them
 Two distinct propositions are presented by the Shades mountain reservoir and East Lake. The reservoir Is very deep. being 40 feet in some places, and in ad- diton is we'll shaded and has much higher altitude than East Lake. The lat ter Is at one of the lowest points in Jones valley is hardly more than 10 feet at its greatest depth and is open to the wind and sun.
 Evaporation at depth of 40 feet, ac- cording to MT. Lehman, is much slower than the 10-foot depth, there being a steady rise of the water from the bottom to the top in the shallow depth, while the cold water settles on the bottom of the deep lake and the warm water rarely reaches bottom.
 While MT. Lehman is receiving no com pensation for the extra work involved in making these tests, he Is very much wrapped up in it, and is doing everything toward securing the best results from it.
 Much trouble has been caused by per sons full of malicious mischief, who seem to take especial delight in filling the tubs with rocks and sinking them, while some one also shot at the wind gauge, denting one of the cups badly.
 These evaporation tests, it is pointed out, will also prove of great benefit to Birmingham in planning the construction of a municipal water works system. While the test is being made by the Tennessee company the results of the test can be secured by persons desiring It without any extra expense.