September 30, 1895.] 



SCIENCE. 



359 



for the future. The Interstate Commerce 

 Law, raih-oad commissious, the appreciation 

 of the vakie of city franchises and the uti- 

 lization of garbage wastes are evidences of 

 progress in public economy. The impor- 

 tance of deciding by a competent authority 

 the relation of our streams to pure water 

 supply and to carrying oif sewage was 

 urged as one of many problems demanding 

 more careful attention. 



In the discussion which followed, E. L. 

 Corthell, in alluding to the author's state- 

 ments concerning competition, considered 

 it unwise for any government to decide 

 what division shall be made between trans- 

 portation by rail and by water. In France 

 it was found necessary to keep up the rates 

 on the railroads in order to save the exist- 

 ence of the canals. Multiplying the means 

 of transportation tends to lower the rates. 

 The Interstate Commerce Commission can 

 prevent the throwing away of money in the 

 unnecessary construction of new railroads. 



Professor O. H. Landreth spoke of the 

 immense investment made for the water 

 supply of Boston and of 25 or 30 towns by 

 cooperation, and Vice-President Kent called 

 attention to the corner in the water supply 

 in northern New Jersey secured by large 

 corporations. 



In a paper on the ' Mathematical Theorj' 

 ■of the Windmill,' by Professor DeVolson 

 Wood, of Stevens Institute of Technology, a 

 formula was derived for the pneumatic 

 energy of the wind upon a sail, and the re- 

 sults were compared with those given in 

 Wolff's Treatise on Windmills. 



Professor Mansfield Merriman, of Lehigh 

 University, presented a valuable paper on 

 ' Partially Continuous Drawbridge Trusses, 

 with a Method of Deducing Formulas for 

 the Reactions. ' The first case of partial con- 

 tinuity considered was the rim-bearing 

 drawbridge without webbing in the panel 

 over the support. The second was that of 

 the double rolling draw, where the webbing 



is continuous but not the chords, and the 

 third case was that of the double swing- 

 bridge, which is a combination of the first 

 two. In all these cases the value of the re- 

 actions deduced were found to be inter- 

 mediate between those for simple and for 

 continuous trusses. 



A paper by Professor J. J. Flather, of 

 Purdue University, gave the results of some 

 ' Experiments on the Flow of Steam and a 

 Comparison with those obtained by Kapler's 

 Formula.' The difference was verj^ small 

 and some of the conditions under which the 

 experiments were made were such as to re- 

 quire additional experiments to be made. 



Professor H. S. Jacoby, of Cornell Uni- 

 versity, read a paper on the 'Design of Fish- 

 plate Timber Joints,' in which formulas 

 were given for the resultant pressure of the 

 side of round bolts or pins against the tim- 

 ber both in the direction of the fiber and 

 perpendicular to that. For yellow pine 

 with compressive stresses of 1100 and 300 

 pounds per square inch on the ends and on 

 the sides of the fiber respectively, the former 

 resultant was 0.627 times the product of the 

 diametral projection of the surface of the 

 bolt by the compressive stress on the ends 

 of the fibers, while that of the latter was 

 0.4 times the same product. The force 

 tending to split the timber when the re- 

 sultant pressure is in the direction of the 

 fibers is one-half of this last amount. The 

 corresponding value of the resultant in the 

 direction of the fibers obtained by experi- 

 ment was found to have an average con- 

 stant of 0.60 instead of the theoretic value 

 of 0.627. The radial angle with the fibers 

 at which the fibers begin to crush sidewise 

 was also determined theoretically and by 

 experiment and the agreement was very 

 close. For the above timber the angle 

 was 15° 37' to 17° 00' in the experiments, 

 the theoretic value being 15° 50'. The 

 tendency to split the timber must be pro- 

 vided for either by transverse bolts or by 



