RURAL ENGINEERING. 589 



Results of some tests to determine the effect of normal and low tempera- 

 tures on the strength of cement mortar (Engin. and Contract., 43 (1915), No. 

 9, pp. 196, 197). — In tests of 1 : 2 cement and sand briquettes it was found ttiat 

 subjecting the briquettes to freezing temperatures after allowing them to set 

 four days at temperatures above freezing materially reduced their strength. 

 The use of a 5 per cent salt solution in place of water slightly increased the 

 strength after 14 days of setting. Briquettes subjected first to freezing tem- 

 peratures and then to nonfreezing temperatures apparently regained their orig- 

 inal strength. 



Use of electricity for irrigation and on the farm, C. H. Williams (Neio 

 York: Nat. Elect. Light Assoc. [1912], pp. 59, figs. 22). — After a general review 

 of the situation rehitive to the use of electricity for irrigation pumping and for 

 farm power purposes, the author summarizes by stating that " from the view- 

 point of the farmer the introduction of electricity into farm methods reduces 

 the cost of production of farm products. The chief saving is in labor and the 

 ability to apply scientific and systematic methods to the industry. From the 

 central station viewpoint it means an off-peak load, a high kilowatt-hour current 

 consumption, and a satisfied customer." 



When the gas engine will not start, E. N. Percy (Power, 41 (1915), No. 9, 

 pp. 299, 300). — Directions are given for systematically following up the trouble 

 when an engine refuses to start, with suggestions for remedying it when located. 



Progress in small farm tractors, L. W. Ellis (Sci. Amer., 112 (1915), No. 

 IJf, pp. 306-308, figs. 10). — This article touches briefly upon tendencies in con- 

 struction, general principles, and the present status of the small tractor indus- 

 try. " In the face of such evident disagreement as to the eventual type the 

 safest course in buying is to investigate all claims thoroughly and insist that the 

 product shall be past the experimental stage and the firm behind it permanent 

 and substantial." 



Report of international competition of raotor tillage machines at Chaouat, 

 Tunis, in 1914 (Compte Rendu du concours International d'Appareils de La- 

 'bourage d Moteurs d Chaouat. Tunis: Dir. G6n. Agr., 1914, PP- 59, pis. 30; ahs. 

 in Internat. Inst. Agr. [Rome], Mo. Bui. Agr. Intel, and Plant Diseases, 5 

 (1914), No. 11, pp. 1485-1481). — This article has been previously noted (E. S. 

 Pv., 32, p. 189). 



Tests of two milking machines, B. Maetiny and P. Vieth (Arh. Deut. 

 LandiD. Gesell., No. 211 (1914), pp. 41, figs. 6).— After thorough testing the 

 judges reported more or less favorably in both cases. 



A shearing shed, sheep yards, and dip, J. S. McFadzean (Jour. Dept. Agr. 

 Victoria, 12 (1914), No. 10, pp. 601-605, figs. 2). — Plans are shown of a shearing 

 shed, sheep yards, and dip, which it is claimed have given complete satisfaction. 



A shearing shed for small flocks, J. W. Mathews (Agr. Qaz. N. S. Wales, 

 26 (1915), No. 1, pp. 5-10, figs. 6). — A sheep-shearing shed to provide accommo- 

 dation for the shearing of 6,000 sheep is illustrated in plan, section, and detail. 



Fences and fencing (Dept. Agr. N. S. Wales, Farmers' Bui. 14 (1914), pp. 

 32, figs. 25). — This bulletin reports a number of experiments with different 

 types of fences and gates, giving specifications for the experimental fences and 

 •describing them in detail. 



In experiments with reference to the use of posts and droppers, several 

 different fences were constructed which are classified in two sections as follows : 

 "" In section 1, which deals with the number of posts necessary for efficiency, 

 pattern A has the posts 8 ft. 3 in. apart (640 per mile) ; pattern B has the 

 posts 16 ft. 6 in. apart (320 per mile), 1 dropper between the posts; pattern C 

 has the posts 22 ft. apart (240 per mile), 2 droppers between the posts; pattern 

 D has the posts 33 ft. apart (160 per mile), 3 droppers between the posts. In 



