1910] RURAL ENGINEERING. 385 



made in the farm acreage, and amounted to an average of slightly less than 

 4 horses displaced on each farm by the purchase of the tractor. 



Poultry buildings: Laying and breeding houses, H. R. Lewis and W. C. 

 Thompson {Neto Jersey Stas. Bui. 325 {1917), pp. 5-102, figs. 5?').— This bul- 

 letin is the first of a series of four which deal with the construction and 

 equipment of buildings iu general demand for use in iKjuUry farming. This. 

 numher deals with laying and breeding houses. 



The first part of the bulletin is devoted to a theoretical discussion of the 

 principles governing the design and construction of poultry houses. 



The second part reports the results of a two-season study of the cost 

 and winter and summer temperature and humidity of six different types 

 of poultry houses. Type-J house is 20 ft. deep and 40 ft. long and is some- 

 what similar in design to the type known as the Wood's fresh-air house. 

 The roof construction is of the half-monitor type, with an entire glass front 

 in the peak. The front is entirely open from 2 ft. above the ground upward, 

 the opening being covered with inch wire. Type-K house is of half-monitor 

 construction, somewhat similar to J except that it is elevated about 2 It. 

 from the ground. The dimensions are 16 by 40 ft. Type-L house, known 

 as the New Jersey multiple unit house, is 20 by 40 ft. in dimension and 

 houses 200 birds. The house has concrete foxmdation walls and is of the 

 shed-roof type. Type-M house is a shed-roof type, 16 by 40 ft., and built 

 entirely of hollow building tile stuccoed with cement plaster on the outside 

 and heavily whitewashed on the inside. Type-R house is a shed-roof type, 

 built entirely of lumber, cheapness being a primary object. It is 36 ft. long 

 by 14 ft. deep. The cost per bird was 77 cts. Type-P house represents a 

 48-ft. section of a 144-ft. laying house and is divided into four pens 12 by 

 16 ft. It is a shed-roof type of frame construction and has a hinged clapboard 

 on the outside of the back wall for ventilation. A concrete floor and foun- 

 dation was built on deep cinders. With reference to cost, the cheapest house 

 was the R type, 77 cts. per bird (not including labor), followed in order by 

 the L, J, P, K, and M types, with 88 cts., $1.08, $1.12, $1.24, and $1.44. 



The temperature studies led to the conclusion that in order to be efficient 

 the average poultry house should be warmer than the outside normal tempera- 

 ture during the winter and cooler than the outside normal temperature during 

 the summer. " These differences in temperature should be much greater on 

 the plus side during the winter than is shown on the minus side during the 

 summer. The use of solid glass sash in the poultry house with no adequate 

 means of continuous ventilation is conducive to frozen combs and cold. 

 An increase in height of the poultry house not only makes the construction 

 more costly, but is apt to make the house colder in winter by Increasing 

 the exposed wall area, thus making possible more radiation. The figures 

 show that a house with some muslin and some glass, of the shed-roof type, 

 with provision for ventilation, is the house which more nearly fulfills the 

 above requirements." During the winter the P type of house was the warmest, 

 followed in order by the L, ]\I, J, R, and K types. The K type was excep- 

 tionally cold. During the summer period the R type was the coolest, followed 

 in order by the M and L types. 



The moisture studies showed the L type to be the driest house, followed 

 closely by the J type. The type-K house was found to be the dampest. 



With reference to sunlight it was found that " a shed-roof house from 16 

 to 20 ft. deep, with openings in the front wall ranging from 2 ft above the 

 ground to 7 ft., is a most excellent arrangement. These openings, distrib- 

 uted almost continually along the front, were found to provide the most 

 138958°— 19 7 



