WATERPROOFING 



6220 



WATERTOWN 



power at least equal to that of Europe and 

 North America combined. 



Power in Waves. The waves of the sea exert 

 almost unlimited power, and could some device 

 be found for using this power in operating ma- 

 chinery the expense of many manufacturing 

 processes might be reduced. For years inven- 

 tors have been working on motors that will 

 Transform the energy of tho waves into me- 

 chanical motion, and such progress has been 

 made as to lead to the belief that in the fu- 

 ture a successful motor of this sort will be in- 

 vented. 



Consult Merriman's Treatise on Hydraulics; 

 Lyndon's Development and Distribution of Water 

 Power. 



Related Subjects. The reader Is referred to 

 the following articles in these volumes : 

 Aqueduct Keokuk, Iowa 



Conservation Niagara Falls and River 



Dam Turbine Wheel 



Hydrostatics Water Wheel 



WAT'ERPROOFING, a method of treating 

 cloth, leather, wood and other substances so 

 that they will shed water. One of the most 

 common forms of waterproof garment is the 

 mackintosh. Woolen and other goods are ren- 

 dered waterproof in one of several ways. Some- 

 times the'y are saturated in soapy water, then 

 immersed in a bath of alum, and finally in 

 solutions of gelatin and galls. In another proc- 

 ess the fibers of the cloth are similarly treated 

 before they are woven. A third process consists 

 in treating cloth with a solution of rubber, so 

 that in the finished product the layer that turns 

 the water lies between an outer and an inner 

 surface of cloth. The mackintosh is thus made, 

 and while it turns water, it also keeps out the 

 air that the body needs, so that it is not health- 

 ful for constant wear. 



The Japanese make waterproof paper um- 

 brellas by dipping paper in a solution of po- 

 tassium dichromate and glue. In Western 

 countries, a solution of shellac in borax is sub- 

 stituted. Leather is treated in a bath of hot, 

 melted paraffin. 



WATER PURIFICATION, pu rift ka' shun. 

 See FILTER. 



WATERSHED, a term sometimes applied to 

 the crest of land which separates the head- 

 waters of two different river systems. Such a 

 water parting is more often called a divide, and 

 is described in these volumes under that head- 

 ing, page 1812. The name watershed is a com- 

 pound of water and shed, shed in this instance 

 retaining its obsolete meaning of part or divide. 

 It is interesting to note that this is the only 



example of the use of shed with its ancient 

 meaning. 



WAT'ERSPOUT, a whirling column of air 

 extending from a cloud to the surface of lake 

 or ocean, rendered visible by the water or 

 vapor it carries. A waterspout is caused by a 

 strong upward draught of air under a cloud. 

 The air acquires a 

 rapid rotary mo- 

 tion as it ascends, 

 and an area of 

 low pressure is 

 produced in the 

 center. Humid 

 air rushing into 

 this low-pressure 

 area is rapidly 

 cooled and be- 

 comes visible as 

 vapor. Thus, al- 

 though water- 

 spouts may draw 

 up some water 

 from the sea near 

 their base, the 

 greater part of 

 the w r ater they 

 contain is fresh 

 .water. Water 

 -often falls in A WATERSPOUT 



All drawings of water- 

 great volumes on spouts are likely to be more 

 iroccolc ^otoinrr fanciful than they are repre- 

 vessels passing se ntative of actual conditions, 

 through water- Solid columns of water surh 

 as the picture suggests sel- 

 spouts, but the dom form ; the substance is 



danger they cloud> or spray> or both " 

 threaten is from the violently whirling wind and 

 not from the water. Waterspouts are generally 

 dissipated after a few moments, like the dust 

 whirls one may see in city streets. See WHIRL- 

 WIND. 



WATERTOWN, MASS., a residential and 

 manufacturing town in Middlesex County, six 

 miles west of Boston, on the Charles River and 

 on the Boston & Maine Railroad. In 1910 the 

 population was 12,875; in 1916, 14,867 (Federal 

 estimate). Interesting features of the town are 

 the state arsenal and public library. There 

 a iv manufactories of paper and paper bags, 

 woolen and rubber goods, waste and shoddy, 

 starch, stoves and furnaces. Watertown was 

 settled in 1630 and was incorporated the same 

 year. It was the first American town to protest 

 against arbitrary taxation, and did so when a 

 levy was collected to build a fort at Cambridge. 

 In 1775 and 1776 the second and third provin- 

 cial congresses met in Watertown. Many colo- 



