388 EXPERIMENT STATTOX RECORD. 



and the wet year of 1907 on fertilized and unfertilized plats of corn, oats, beets, 

 and carrots, using 5.9 in. and 11.8 in. of water. Irrigation was decidedlj- bene- 

 ticial in the dry j-ear and the beneficial effect was increased by the addition 

 of fertilizers, but in the wet year irrigation not only was not beneficial but even 

 resulted in a decreased yield, due, it is thought, to a leaching out of the fertiliz- 

 ing matter from the soil. 



Measurement of water, E. T. Tannatt and R. D. Kneale {Montana Sta. 

 Bui. 72, pp. S-JjO, pis. 7, figs. 7). — This is a revision and extension of Bulletin 34 

 of the station (E. S. R., 14, p. 94), describing the various units employed in meas- 

 urements of water, and the construction and proper use of weirs and flumes, 

 and also including tables for calculating the discharge over weirs. The use 

 of the second-foot is strongly advised in order to avoid misunderstandings. 

 Common errors made in measuring devices and reasons for failure are pointed 

 out in the text and illustrated by photographs of weirs actually constructed. 

 ^Mention is made of an automatic measuring instrument patented by E. B. 

 Howell for accurately measuring the depth of water on a weir. 



Preliminary tests of sugarhouse machinery, E. W. Kerk (Louisiana Stas. 

 Bui. 107, pp. 3-16, figs. 6). — This contains results of preliminai'y tests made 

 to get information as to the relation of capacity to energy consumed and as to 

 the efficiency of machinery peculiar to sugarhouses. 



The methods of testing sugar-mill work are discussed. That of determining 

 the volume of juice in the bagasse per unit weight of fiber in the bagasse is 

 deemed impracticable because of difficulty in determining the density of the 

 juice. The method of using percentage of weight of moisture in the bagasse is 

 considered accurate enough for practical purposes. 



Tests were made on a mill of the 6-roller type in which the mill rolls were 

 34 by 84 in., and there was a pressure of 330 tons on the front mill and 390 tons 

 on the back mill supplied by the hydraulics. The indicated horsepower of the 

 engine, when operating the mill, is compared with its rated capacity and also 

 with its indicated horsepower when under no load. The friction of the mill 

 as thus determined shows a probable loss of but 5 per cent in mill friction. 



Tests were also made of a cane carrier operated by direct current electric 

 motor. The carrier was 600 ft. long, the vertical lift 27 ft., and the cane was 

 being carried at the rate of 49.2G tons per hour during the tests. The horse- 

 power figured from measurements by voltameter and ammeter, compared with 

 the useful work done, shows an efficiency of 13.7 per cent, 86.3 per cent being 

 lost In friction. 



A set of four 30 in. centrifugals of '97 model of Weston type, used for drying 

 second sugars, and a set of five 40 in. Weston centrifugals, used for drying 

 first sugars, were tested to determine the power required both for starting 

 and running. Power for the 30 in. centrifugals was supplied by direct current 

 electric motor and for the 40 in. by an automatic high-speed engine. The 

 starting power of the motor was measured by noting the maximum ammeter 

 reading, and the running power by the reading when the needle came to rest. 

 The results show that the running power is about 25 per cent of the starting 

 power. The power required to start indicates the capacity of the source of 

 power, but not the energy necessary to be supplied by the boiler in the case 

 of a steam engine. 



It was attempted to measure the horsepower of the engine by means of a 

 steam-engine indicator and a speed indicator, but this method proved unsatis- 

 factory because of irregularities " due to the fact that the speed counter could 

 not be depended upon to indicate accurately the speed at the moment of starting. 

 A tachometer will be procured for future use." 



