BUREAU OF PUBLIC ROADS. 487 



all others, the farmer must rely on his own judgment. Above others, 

 his plumbing installation should be simple, serviceable, safe, and 

 inexpensive. This bulletin supplies just the information needed. 

 Simple directions are given for determining pipe sizes. The most 

 suitable fixtures and kinds of pipe with costs are discussed suffi- 

 ciently to enable anyone to choose wisely. Plumber's tools and their 

 use and methods of roughing-in, supporting, and protecting plumb- 

 ing from frost are discussed and illustrated. The housewife will 

 especially apreciate the sections devoted to hot-water supply and 

 to care of plumbing fixtures necessary to preserve their life and 

 sanitary qualities. The bulletin contains many illustrations and 

 will go far toward enabling any farmer who so desires to do his 

 own plumbing. It will prove useful whether the house is humble 

 or pretentious, whether old plumbing is to be renovated or new is 

 to be installed. Improper plumbing may be a source of great an- 

 noyance, if not a danger to health. 



Lantern slide series No. 104, comprising 48 slides with syllabus 

 entitled " Farmstead water supply," was prepared for the States 

 Relations Service. 



Further study and analysis of data obtained in previously made 

 investigations of the use of tractors led to the preparation of a 

 bulletin on the utilization and cost of using tractor-drawn imple- 

 ments. The manuscript has not yet been submitted for publication, 

 but it is thought that the bulletin will be helpful to those who 

 practice power farming or who contemplate a greater use of power. 



Whether a motor truck would prove a profitable investment is a 

 question that is something of a stumblingblock to many farmers. 

 The experience's of a large number of farmers in the New England 

 and Central Atlantic States have been put into a bulletin, which 

 has been submitted for publication. The report, which brings up to 

 date data contained in a previous bulletin, should be of material 

 assistance to those who are considering the purchase of a truck. 



Other bureaus of the department are engaged in investigations 

 which involve the erection of specially designed buildings or equip- 

 ment for exj)erimental purposes. Plans for such construction were 

 prepared by this bureau. The new central heating and power plant 

 and an auxiliary water-supply system at the Arlington Experi- 

 mental Farm were the most notable undertakings of this kind. The 

 results of other investigations of several bureaus affect the design 

 of farm and rural industrial structures. In cooperation with those 

 engaged in such investigations this bureau has prepared building 

 plans and designs of minor equipment. 



Continuing the cooperation with the Bureau of Entomology in 

 cotton-boll-weevil control, this bureau assisted in the engineering 

 work involved in the investigations. The work of the year included 

 the development of mechanical apparatus for the distribution of 

 calcium arsenate from airplanes, as there was no apparatus avail- 

 able that was suitable for this work. A public patent on the dis- 

 tributing apparatus was secured. An investigation of types of air- 

 planes to determine the one best suited to dusting cotton was made. 

 The experimental work with airplanes has opened up new possi- 

 bilities in the development of dusting machinery and may result in 

 the development of new types of machines, better adapted to the 



78007— AGE 1923 32 



