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GLEANINGS IN BEE CULTURE 



Oct. 1 



FIG. 1.— LAKE IN BOULDER CANYON, COL., HELD BACK BY THE IMMENSE CONCRETE DAM. 

 This volume of water not only furnishes 21,000 horse power, but supplies water for irrigating 12,000 acres 

 of land. 



the spring they are pulled up the steps in 

 the same manner. 



The hives in the apiary face the east; and 

 as there is no room for trees a bush known 

 as summer evergreen, or the burning bush, 

 is planted at the south side of each hive to 

 protect the bees from the sun. This is very 

 pretty, and furnishes a splendid shade 

 within a few weeks. 



Osborne, Kan. 



PROSPECTS FOR IRRIGATION IN COLO- 

 RADO. 



How Irrigating-reservoirs and Power-plants are 

 Combined. 



BY WESLEY FOSTER. 



For a number of years government en- 

 gineers as well as engineers for private com- 

 panies have been working on the problem 

 of using the water of the Rocky Mountain 

 streams for power in generating electricity 

 and at the same time save the water for ir- 

 rigation. If the reservoirs are built out in 

 the valleys and on the plains, the power is 

 lost unless the generating-plant is an en- 

 tirely separate affair. This makes the ex- 

 pense much greater than if the reservoir is 

 built high up in the mountains and the 

 water piped down a thousand feet or more 

 to the immense turbines or water-wheels 

 which turn the electric generators, and then 

 carried in ditches out to the land to be irri- 

 gated in the valley. 



It is necessary for a power-plant to have 

 a steady and constant supply of water 

 throughout the year, and for this reason 

 immense storage reservoirs are needed. 

 Fig. 1 shows an immense concrete dam 18 

 miles up Boulder Canyon, built across the 

 canyon at a narrow place. About 525 mil- 

 lion cubic feet of water is impounded, or, in 

 other words, 12,000 acre feet, which means 

 enough to cover 12,000 acres of land with 

 one foot of water. An acre of land requires 

 about an acre foot to raise a crop successful- 

 ly, so that this dam holds backwater enough 

 to irrigate 12,000 acres. But the water for 

 irrigation is not needed during the fall, win- 

 ter, and spring, although it is needed for 

 power continuously,, so the power company 

 is building a large reservoir out on the 

 plains, several miles from Boulder, to hold 

 the water that must be used during the 

 months when no irrigating is being done. 

 This makes a very economical plan, and, 

 when in full operation, the water will be 

 saved for irrigating, and all the power from 

 this fall utilized. 



The dam above referred to is now like a 

 great boulder or rock concrete, 177 ft. high, 

 G24 feet long, 120 feet thick at the bottom, 

 and 16 feet thick at the top. About 133,000 

 cubic yards of concrete were required, and 

 many months' time elapsed during its con- 

 struction. It is like a great rock wedge 

 placed in a wedge-shaped canyon, and it so 

 effectually stops the water that it makes a 

 lake more than a mile long and about half 

 a mile -wide. 



Fig. 2 hardly conveys an idea of the im- 

 mensity of the affair. It might be likened 

 to the pyramids of Egypt, but it will infi- 



