AGRICULTURAL ENGINEERING. 695 



AGRICULTURAL ENGINEERING. 



One year's -work done by a 16-foot geared windmill, F. H. King 

 (Wisconsin Sta. Bui. 68, pp. 44, figs. 13). — The work done by a lG-foot 

 geared steel power mill as well as the total wind movement, hour by 

 hour, for the year ending March 6, 1898, are recorded in this bulletin. 

 The mill is placed on the tower of the agricultural physics laboratory 

 of the station and — 



" Stands on a steel tower with its axis 22 ft. above the deck, 82 ft. above the ground 

 outside the building, and about 106 ft. above lake Mendota. . . . The building is on 

 the north slope of a hill, near its summit. It was impracticable to arrange the 

 pumps and other machinery in the laboratory in such a way as to transmit the power 

 directly to the driving shaft and an offset had to be made. . . . [This was done by 

 meaus of] 14-inch Hanged pulleys carrying a 6 inch rubber belt. . . . At the bottom 

 of the 1-inch driving shaft a foot gear transmits the power to a 1^-inch horizontal 

 shaft from which the pumps and other machinery are driven. ... It will be observed 

 that this arrangement has necessitated two transfers of power besides that in the 

 head of the mill itself." 



The work of the mill was measured by pumping water from a reser- 

 voir having an area of 285 sq. ft. into a measuring tank holding 141.2 

 cu. ft. 



"When the measuring tank was filled to the top of the siphon it was automatically 

 emptied. By means of a float . . . arranged to work the pen on a chronograph, a 

 record was secured of the number of times the tank was emptied each day and of 

 the interval between each emptying. The mean height to which the water was 

 lifted was, during March and April, 1897, 10.5 ft., but after that date the lift was 

 increased to 12.85 ft." 



The pumps used were (1) a reciprocating pump with a 14-inch piston 

 and a 9-inch stroke; (2) a bucket pump having a capacity of 120 gal. 

 per minute, and (3) two pumps of the centrifugal type. Nearly all the 

 work, however, was done with either the first or the second or the two 

 combined. By combining the pumps in various ways it was possible 

 to secure more work than by any one pump alone, but it was impossible 

 to secure the maximum amount of work the mill was able to do. 



"It frequently happened when the mill was left with one pump that during the 

 night the wind became strong enough to carry two, but it did not get them until 

 the next morning. So, too, when in the evening the wind was strong enough to 

 work the two pumps and it was left with them the wind would go down until the 

 two could not be handled, when if but one had been left this could have been worked 

 all right. . . . 



"The total amount of water pumped during the 365 days was 24,433 tanks, each 

 holding 141.2 cu. ft. This is at the mean rate of 2.789 tanks each and every hour of 

 the day, or 393.8 cu. ft. per hour and 6.562 cu. ft. per minute. Expressed in another 

 way, -the water pumped during the year is sufficient to cover 79.1 acres 12 in. deep 

 or a rate of 2.6 acre-inches per day for the full year. . . . The largest amount of 

 water pumped during any single day in the year was 39,540.2 cu. ft., which is a rate 

 of 27.04 cu. ft. per minute." 



Calculating the work done to 10-day periods it was found that "the 

 smallest amount of water lifted 10 ft. high in 10 days was enough to 

 cover 9.87 acres 1 in. deep, and this occurred from July 28 to August 7, 



