486 EXPERIMENT STATION RECORD. [Vol.43 



Electric light and power in the farm home, A. M. Daniels (U. S. Depi. 

 Agr. Yearbook I'Jl'J, pp. 223-238, Jifjs. 10). — Infoniiation is given on the uses of 

 electric light and power on the farm and the installation of wiring systems. 



The design of hot water heating systems, I-II, W. Ehklich {Building Age, 

 1,2 (1920), Nos. 1, pp. 33-35; 3, pp. 30-33, flgn. 3).— Practical methods for pro- 

 portioning the radiators and sizing the mains and branches to insure successful 

 installation are presented. 



Air conditioning in private houses, K. G. Smith (Iowa Agr. Col. Off. Pub.. 

 18 {1919), No. 22, pp. 7, fig. 1). — Information is given on methods of supplying 

 moisture to the air in houses in winter. It is stated that the humidity of the 

 air in a dwelling house should not be less than 30 per cent. 



" If the temperature is zero and the outdoor humidity at the average of 70 

 per cent, it requires about 1 gal. of water every 12 hours to properly moisten 

 the air required by one person when it is warmed to a room temperature of 

 70° F. The moisture must be supplied to the air in the form of vapor or 

 steam. To evaporate water with sufficient rapidity to supply this moisture 

 requires either a large surface, a high temperature, or both. Pans which hang 

 on the back of a radiator do not have a lai'ge surface and are not highly heated, 

 hence they are not very effective. A small tube, attached direct to the radiator 

 and discharging steam into the room is also used. This supplies vapor faster 

 than the pans, providing there is steam pressure. ... 



" One of the most effective pans made has a water space in the middle and a 

 wick to give a large evaporating surface. . . . Pans may be made somewhat 

 more effective by placing sheets of blotting paper or asbestos beneath them 

 and punching a needle hole in the bottom of the pan. The paper absorbs the 

 water and increases the evaporating surface." 



Wai'm-air furnace water-pan equipment is also described. 



RURAL ECONOMICS. 



The agriculture of Ohio (Ohio Sta. Bui. 326 {WIS), pp. 5-Ul, flOS. 163).— 

 Following a preface (pp. 5, 6) by C. E. Thorne, Pa4"t I of this bulletin consists 

 of A History of the Agriculture of Ohio by W. A. Lloyd (pp. 7-S6). In outline, 

 its development is said to begin with an era of preparation, including the 

 period of the aborigines from earliest times to 17SS, and that of the pioneers 

 extending down to 1832, and to pass through an epoch of formation in which 

 were the periods of extension, 1832-1865, and of development, 1865-1900, to 

 an epoch of stabilization with its periods of reorganization and of cooperation. 



Part II (87-246), ''by J. I. Falconer, is a detailed statistical study of Ohio 

 Agriculture from 1850 to 1910, covering the development of live stock industries 

 and farm crops in Ohio; the use of fertilizers, size and tenancy" of farms, and 

 the development of land values and prices, as well as of railroads, cities and 

 rural population, farm machinery, and the various agricultural regions. 



Part III gives statistics of Crop Production by Counties in Ohio since 1850 

 (pp. 247-427), by C. E. Thorne, followed by an abridged description of the 

 Principal Soil Types of Ohio (pp. 428-437), previously noted (B. S. R., 34, 

 p. 322). 



Minutes of the farmers' cluh of Pennsylvania, E. B. Morris {Philadel- 

 phia: J. B. Lippincott Co., 1920, pp. XII +361). —'Notes relating to this organi- 

 zation that appeared in the local paper at intervals between November, 1849, 

 and July, 1859, as well as minutes of the meetings up to and including Decem- 

 ber, 1919, are published here. 



Lessons from the history of the public domain, C. Tallman (In Soldier 

 Settlements m the South. Savannah, Ga.: South. Land Cong. Proc., 1918, pp. 



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