HUKAi. l■;^'(;IN^:ERlN(;r 7S3 



(he piiiu|) ])roi)(»rtioiit'il to the work. Tlic ciilfuliitioiis for total (luantities raised 

 are based on an assmiied average of at least S hours ])er day, with a wind 

 sntliciently strong to work (lie mill at avera.^re sjjeed. which in |)i-;i.-(ife is found 

 to he a safe assumption. 



With regard to wind velocity it is stated that intcrniittent working only can 

 be expected willi velocities of ."> to 10 miles per hour. With velocities of 10 to 

 15 nules ])er hour stcidy working at .ihout average S])eed should he obtained. 



A typical e.\'anii)le oi' a village sui)ply pumped by wind power is given, from 

 which the following ])articulars are absti'acted : Wind wheel IS ft. diameter, 

 with hinged canvas sails, working a single-acting, deep-well pump 4^ in. diameter 

 and S-in. stroke, well .">.") ft. deep: total lift from water level to reservoir VAO ft, 

 e.\clnsi\-e of friction. Reservoir cai)acity .'!0.(I00 g;iL. ciinixiilenl 1o (i days" 

 supply for a jioimlation of 400 p(>oi)le. Auxilinry iiincliinery consisls of a 

 triplex pumji, worked l)y horsepowei'. 'Plie cdst df pumping was foinid to be less 

 than .$iri ])er annum. Cost <d' windmill, horse gear, pumps, and well fittings, 

 .'Fl,T2r», and total cost of wIkjIo scheme, .fll.OOO; cost of attendance, .$2.") i)er 

 annum. 



The trials of suction gas plants at Derby, 1906 {KuniDccr (Jjoiidoii), 102 

 H!)06). .Vo.v. .id^H, pp. 608-6JI; .HiiiU, pp. (ji'j, H.id). — The Royal Agricultural 

 Soci(>ty conducted a number of tests of suction gas plants in June, lOOd, at th«! 

 annual slio\\- at Derby, England. The declared object of these tests was to 

 dett'rnnne as well as possible in the short time allowed whether suction gas 

 plants would work as reliabl.v under agricultural conditions as the steam engine 

 and with as small an amount of attendance as the oil engine. A satisfactory 

 answer to these questions would jirovi' the suitability of such plants for agri- 

 cultural purposes, since their advantages from the standpoint of economy are 

 accepted without question. The deciding factor in judging the merits of the 

 different plants tested was their simplicity, since it was expected that the plants 

 in many cases would be placed in charge of farm hands who would be vmahle 

 to make adjustments which lead to small economies in working. 



The regulatiims surrounding the tests were fairly stringent, it being intended 

 to duplicate, as nearly as possible, the running conditions of actual practice. 

 The i)lants tested were limiti'd to sizes ranging at and below 20 horseiiower, 

 and a variation of not more than 5 per cent from the declared horsepower was 

 allowed. The engines wei'e run for consecutive hours imder constant load, 

 when tliey were shut down for the night, to resume rmniing next day. Special 

 attention was paid to the following points : (1) Attendance necessary ; (2) gen- 

 eral design, including facility of cleaning and si)ace occupied; (3) regularity 

 of work; (4) fuel consumption and water consumi»tion ; (5) price; (U) rela- 

 tive proportions of gas producer and engine; (7) volume swept by piston relative 

 to brake horsei)o\ver. 



The results of observaticnis uikju several of these points are iu-ietly given, as 

 follows : 



1. It was found that, without considering the additional hel]) in tiu'ning over 

 the engine at starting, one attendant only was reipiired. .uid his time could 

 largely l)e spent in other duties. Although less manual labor is i-e(|uired than 

 in the case of the steam engint' very intelligent care is necessary, however, to 

 I)roduce gas of good (piaiity. 



3. Although regidarily of working, so far as the engine was concerned, was 

 found to i)e dependent uiton the amount of tar ])resent in the gas. the gas prod- 

 ucer itself is evidently the portion of the i)lant re(|uiring most attention, since the 

 gas is made as reipiired and conse(pientiy ditiicnlty is experienced in responding 

 quickly to changes tvoiu light to full load. 



