396 



SCIENCE 



[N. S. Vol. XXXIII. No. 845 



Atlantic and one in ilie Indian, by cold ocean cur- 

 rents. Hence, each of these five places is the seat 

 of a permanent high or anticyclone with Its at- 

 tendant permanent circular winds. 



An Indicator for Determining the Efficiency of 

 Aeroplanes or Kites: S. P. Ferguson, Reno, 

 Nev. 



The author has devised a compact self-recording 

 instrument for indicating continuously the aiigle 

 of incidence and lateral inclination of an aero- 

 plane or kite together with the velocity, and the 

 lateral and vertical oscillations in the direction 

 of the wind with reference to the flying machine 

 upon which it is carried. This instrument is 

 based upon the kite-meteorograph designed in 

 1905 by the author. 



Determina-timv of Altitudes of Aeroplanes by 



Triangulation: R. W. Wilson, Cambridge, 



Mass. 



This paper contains an account of observations 

 made by two methods to determine the maximum 

 height reached by aeroplanes and a comparison of 

 the results obtained at the Harvard Aviation 

 Meet. 



By one method observations were made with 

 sextants in a fixed vertical plane which the 

 aviator was to cross at his greatest altitude. 

 Simultaneously observations were made by the 

 other method in which theodolites were placed at 

 the extremities of a base-line three miles south of 

 the field. 



Technical Education in Aeronautics : C. H. Pea- 

 body, Boston, Mass. 



Technical education must eventually be offered 

 for aeronautical engineers; the question is 

 whether now is the time. The phases of this 

 question are financial support, subject matter for 

 instruction, method of securing teachers. The 

 writer favors training a teacher for the purpose, 

 and the establishment of undergraduate courses 

 of instruction now. He offers a suggested course 

 parallel to a course for naval architects. 



A Program of Aeronautical Research Work, vnth 



Special Reference to what may be don-e at th-e 



Colleges: A. A. Merrill, Boston, Mass. 



In this paper the work suggests four general 



lines along which research could be profitably 



conducted: (1) the problem of construction, (2) 



the problem of efficiency, (3) the problem of 



power, (4) the problem of stability. 



In connection with each problem the author 

 pointed out just what research work is necessary 

 and to what extent the colleges are fitted to 

 undertake this work. 



t'<oiiic Experiments on the Pressure of a Current 



of Air on Certain Surfaces: G. Lanza, Boston, 



Mass. 



The paper explains the need of an apparatus 

 consisting of a blower, for the production of a 

 current of air, and of a tube for directing this 

 current against the surface to be experimented 

 upon. Also the means of obtaining a current free 

 from gusts, and having a uniform velocity at all 

 points of the cross-section of the tube. 



Reasons are also given why the experimental 

 surface should not be placed inside the tube, but 

 should be located outside of and near its mouth. 



The value of K in the formula P = KV- was 

 found as a result of these experiments to be 

 ii = 0.0031, whence P:^ pressure in pounds, and 

 V = velocity in miles per hour, the experimental 

 surface being a plane surface one foot square, 

 placed at right angles to the current. 



The results are also given which were obtained 

 by an investigation of the vortex formed under 

 the prow of a surface formed to approximate 

 the underside of the wings of certain birds, and 

 placed at small angles of inclination to the cur- 

 rent. The need of a larger apparatus of the same 

 kind is urged. 



The Increase of Wind-pressure on a Normal Sur- 

 face with Height: A. H. Palmer, Hyde Park, 



Mass. 



The increase of wind-pressure on a normal sur- 

 face with increasing height is of considerable 

 importance in aeronautical construction. From 

 the known decrease of atmospheric pressure with 

 height, and the wind-velocity in the free air ob- 

 tained by means of kites and observations of 

 clouds at Blue Hill Observatory, the wind-pres- 

 sure in pounds per square foot upon a vertical 

 plane has been computed and has been plotted in 

 a diagram. 

 Normal Stress and Resultant Pressure: A. ¥. 



Zahm, Washington, D. C. 



Extract from forthcoming book on " Aerody- 

 namics " by Mr. Zahm. 

 Early Attempts to Navigate the Air: J. J. Green, 



Notre Dame, Ind. 



Outline of history of aerial navigation from 

 the time of Daedalus and Icarus through the 

 middle ages down to the invention of the balloon. 

 Scientific work done with the balloon. Its use 

 by the postal authorities during the siege of 

 Paris. Langley, Lillienthal, Chanute, Ader and 

 their work; brief statements except in case of 

 Ader's work. G. W. Bissell, 



Secretary 

 East Lansing, Mich. 



