1919] RURAL ENGINEERING. 487 



1.66 miles per hour, and 0.401 acres were plowed per hour. The fuel con- 

 sumption per acre was 3.71 gal. of kerosene, and the cost per acre plowed and 

 harrowed was 70.9 cts. 



Demonstrations of tractors and plows ( Trans. Highland and Agr. Soc. Scot., 

 5. ser., 30 (WIS), pp. 295-358, figs. 29).— This is a report of tests of 29 different 

 tractors with a number of types of plow on stubble and grass land, consisting 

 in one case of a deep free loam with occasional earth-fast stones and in an- 

 other of a free loam overlying a clay subsoil. The stiffest grade encountered 

 was 1 in 5.2. Of the 29 machines which took part in the demonstration 15 

 ran on four wheels, 6 on three wheels, 4 on caterpillar tracks, and 4 were 

 single unit machines. Twenty-five machines were driven by paraffin, 3 by 

 petrol, and 1 by steam. The weights varied from less than 3,000 lbs. to over 

 8,000 lbs. The depth of plowing required varied at the different points from 

 6 to 8 in. for grass land and from 7 to 9 in. for stubble. The general con- 

 clusions derived from the results of this test are as follows : 



The weight of the tractor should not exceed 3,000 lbs., and the horsepower 

 should not be less than 20-brake horsepower. Caterpillar tracks did not show 

 any advantage in gripping power over the best type of wheels. Well designed 

 spuds appeared preferable to either spikes or bars on wheels. Exposed gear 

 drives on wheel tractors and excessive wear on caterpillar tracks tended to 

 impair durability. Spring attachments between tractor and plow, with a re- 

 lease device in case of severe shocks, appeared desirable. It was found that 

 the point of attachment should be variable vertically and horizontally. Speeds 

 of 2i and 4 miles per hour forward, with reverse, appeared to be most gen- 

 erally useful. Complete vaporization of paraffin was not generally obtained, 

 and it is thought probable that the use of petrol will be more satisfactory 

 under normal conditions. Handling and turning did not usually prove difficult. 

 Single unit machines had the advantage that the implement operated was 

 directly under the observation of the driver. Lighter tractors and single unit 

 machines occupied less time and space in turning. It was found that plows 

 must be adjustable to varying widths as well as to varying depths. Where the 

 tractor and plow were separate an automatic lift was found desirable. A 

 guide wheel to regulate width of leading furrow was also found desirable. It 

 is concluded further that under the conditions of the test the price of a tractor 

 should not exceed £300 (less than $1,500). 



Homemade header attachment, P. E. Fullek (Mo'nt. Col. Agr. Ext. Serv. 

 [Pub.}, No. 27 (1918), pp. 4, figs. 2). — A homemade header attachment for the 

 ordinary binder is briefly described and illustrated. 



Potato planting machinery in New York, E. V. Hardenbtjeg (Cornell Coun- 

 tryman, 16 (1919), No. 2, pp. 75, 76, fig. 1). — It is stated that approximately 75 

 per cent of the acreage in the four principal potato areas of New York is 

 planted by machine planters. 



A study of comparative costs of machine and hand planting on 360 potato 

 farms showed that machine planting was more economical on farms producing 

 5 acres or more of potatoes. A study on 635 farms of the potato yields ob- 

 tained from the use of one and two-man planters showed, with one exception, 

 that the yields per aci'e were higher where two-man planters wei'e used. 



Farm mechanics, H. A. Shearer (Chicago: Frederick J, Drake <£ Co., 1918, 

 pp. 250, figs. 239). — This is a popular treatise on machinery and its use in the 

 saving of labor on the farm, and includes sections on tools, shopwork, driving 

 and driven machines, farm waterworks, and sewage disposal, and care and 

 repair of farm implements. It is obvious that considerable of the information 

 has been compiled from somewhat out-of-date publication.s. 

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