634 



SCIENCE. 



[N. S. Vol. XV. No. 381. 



more has been done in the study of the prin- 

 ciples of safety and stability of the flying 

 machine than was accomplished by Liliendahl, 

 by Pilcher and by Chanute, in Germany, in 

 England and in the United States, respective- 

 ]y. It is almost ten years since Maxim mounted 

 his machine and actually flew a short distance 

 at high speed and with disastrous results to 

 his machine and danger to himself, and the 

 experiment has not been repeated. Langley's 

 experiments and discussions have provided us 

 with a correct knowledge of the physical and 

 the mathematical principles involved in flight, 

 so far as measures of lift and of head resist- 

 ance are concerned, but the applied theory is 

 still to be illustrated in any full-sized and 

 practically useful apparatus. The steadying 

 action of the balloon is relied upon wherever, 

 as in the case of Myers, of Frankfort, N. T., 

 the oldest and most successful among pioneers 

 in this line of development, and in that of 

 Dumont, the inventor and exploiter, one seeks 

 to traverse the air safely. Only when stability 

 and permanence of stability can be insured 

 can aviation become practicable. The experi- 

 ments of the Messrs. Wright, of Dayton, O., 

 mostly conducted at the shore on the coast of 

 ISIorth Carolina, have seemingly advanced our 

 knowledge greatly in this direction. 



The Wright apparatus is double-decked like 

 that of Chanute, but the endeavor was to pro- 

 vide for direction and balance without shift- 

 ing the body of the aviator with every change 

 in the direction and force of the wind. It was 

 found that practice would make perfect the 

 experimenter here, as in every other field of 

 action; that constant practice should be pro- 

 vided for; that the horizontal position should 

 be assumed by the operator and that it is 

 actually practicable; that a small steering 

 vane could be set in advance of the aeroplanes 

 adopted and successfully employed in direct- 

 ing flight and in counteracting the fluctuating 

 action of the wind in disturbance of the posi- 

 tion of the center of pressure on the planes; 

 that twisting the planes is a more effective 

 method of meeting the changes of pressure 

 produced by wind disturbances of small extent 

 than any system of movement of the body. 



The machine finally adopted spread 308 



square feet of canvas, was 22 feet long, 7 feet 

 high and double-decked. The wings or planes 

 were given the section observed in the wing of 

 the pigeon, i. e., slightly curved from front to 

 rear and with the curvature sharply increased 

 at the leading edge in a degree determined, 

 necessarily, by ex-periment. Gliding or soar- 

 ing was successfully attempted with this con- 

 struction, in winds of velocities ranging from 

 1] to 27 miles an hour, and distances were 

 attained with small elevation at the start up 

 to a maximum range of about 400 feet; the 

 operator finding no special difiiculty in either 

 steering or balancing the machine. The rate 

 of drop was as low as two feet per second in 

 some instances. 



These investigations have probably dis- 

 closed a method of study of the action of the 

 aerodrome which is comparatively safe, which 

 permits the investigator to dispense with a 

 motor if he so desires during the preliminary 

 work of tracing out the principles underlying 

 stability and safe operation of the aviator in 

 a moving atmosphere. The work is a distinct 

 contribution to existing knowledge in this 

 fascinating field of research. 



E. H. T. 



U. 8. CIVIL SERVICE EXAMINATIONS. 



The Civil Service Commission announces 

 an examination on May 6 and 7, for positions 

 in the Philippine service of agricultural 

 chemist, analj'tical chemist, physical chemist, 

 physiological chemist and pharmacologist with 

 salaries of $1,500 to $1,800. In announcing 

 this examination, the Commission sends the 

 following statement : 



These examinations offer an excellent oppor- 

 tunity to enter a service which has many attract- 

 ive features and to see a most interesting part of 

 the world. The Philippine Service is classified, 

 and the law contemplates promotions on the basis 

 of merit from the lowest to the highest positions. 



Thirty days' leave of absence is granted each 

 year, exclusive of Sundays and holidays, and those 

 employees who are promoted to $1,800 per annum 

 are entitled to thirty-five days, or about forty days 

 including Sundays and holidays. Leave is also 

 cumulative, and at the end of three years those 

 who have to their credit cumulative leave for two- 

 years may visit the United States without having 



