188 EXPERIMENT STATION EECORD. 



At the experiment station farm at Lexington 9 green stumps averaging 22 in. 

 in diameter were blown at an average cost of $1.5G per stump, lOJ sticks of 

 dynamite per stump being used. Of these stumps 3 black oak averaged 45 

 in. in diameter and were blown at a total cost of $3.52 per stump, the average 

 number of sticks of dynamite used being 23J. 



The amount of dynamite required to blow stumps of the same kind in the 

 same soil does not vary directly with the diameter, but more nearly with the 

 square of the diameter, or in other words, with the area of a cross section of 

 a stump. 



Sanitary dairy barns, O. Erf (Ohio State Univ. Bui., Uf {1910), No. 7, pp. 

 132-166, pis. 2, flgs. 25).— A lecture at the Cincinnati Milk Show and Dairy 

 Institute held in May, 1909. The author discusses what constitutes a sanitary 

 barn, the materials of which it should be built, and equipment for economizing 

 labor and improving sanitary conditions. Several barn plans are illustrated 

 and described. 



A unique Mexican silo, O. Erf (Hoard's Dairyman, 1^2 {1911), No. ^3, p. 

 1321, flgs. 3). — A brief description of a silo 30 ft. in diameter and 70 ft. deep, 

 which was dug on a hillside. A great variety of crops were grown to fill this 

 silo, though the 2 principal crops were barley and oats. The silage is taken 

 out through a tunnel projected into the hill. 



Poultry house construction, J. G. Halpin and C. A. Ocock (Wisconsin 

 Sta. Bui. 215, pp. 3-32, figs. 23). — This contains a discussion of the site for the 

 poultry house, and details of construction, including types of roof, floor, walls, 

 nests, dropping boards, and watering- devices. Plans are given for a portable 

 house for small lots, a brooding house, a breeding house, and a laying house. 



Up-to-date poultry houses and appliances, edited by H. Teafford (Spring- 

 field, Ohio, 1911, pp. 112, figs. 86). — A great variety of poultry houses, brooders, 

 feeding troughs, drinking fountains, and other appliances are illustrated and 

 described. 



Naphthalene in road tars. — I, The effect of naphthalene upon the con- 

 sistency of refined tars, P. Hubbard and C. N. Draper (U. 8. Dept. Agr., 

 Office Pub. Roads Circ. 96, pp. 12, figs. 2). — As the degree of fluidity of a tar 

 intended for road construction is of great importance, a study was made for 

 the purpose of determining the relation of the naphthalene content of such 

 materials to their consistency. The effect of naphthalene upon the consistency 

 of water-tar pitch was also studied. 



As the result of this work the authors point out that " while at the present 

 time it does not seem advisable to draw very definite conclusions, the foregoing 

 results nevertheless strongly indicate the following facts: (1) That the fluxing 

 value of naphthalene for tar pitches is somewhat greater than, although quite 

 similar to, the heavier naphthalene-free tar distillates, until the mixture be- 

 comes saturated with naphthalene; (2) that for the harder tar pitches the 

 addition of very small percentages of naphthalene will produce a marked 

 increase in fluidity of the resulting product; (3) that for the softer pitches 

 the addition of naphthalene in small quantities causes less increase in fluidity 

 than for the harder pitches; (4) that where naphthalene is added beyond the 

 point of saturation a rapid decrease in the fluidity of tars at temperatures 

 below the melting point of naphthalene is observed, but at temperatures above 

 its melting point the fluidity continues to increase. . . . Within a reason- 

 able degree of accuracy, it should be possible to foretell, by reference to the 

 curves which [are] given, what consistency to expect from the addition of a 

 given percentage of naphthalene to a tar pitch or refined tar of known consist- 

 ency irrespective of the free carbon content of the tar." 



