180 



SCIENCE 



[N. S. Vol. XL VI. No. 1182 



marized in the Engineering Supplement of tlie 

 London Times. 



It is said that owing to the numerous 

 changes and development in the design and 

 construction of aircraft an increasing number 

 of special problems constantly presented them- 

 selves for investigation, and these have closely 

 occupied the attention of the staffs engaged in 

 experimental work at both the National Phys- 

 ical Laboratory and the Royal Aircraft 

 Factory. In addition to aerodynamical re- 

 search, much attention has been given to ques- 

 tions relating to engines, materials of con- 

 struction, strength of construction and design, 

 instruments and accessories, as well as to 

 methods of attack of aircraft from aircraft and 

 other matters. 



In the new 7 ft. air channel at the National 

 Physical Laboratory an air speed of 85 ft. 

 per second can be reached with an expendi- 

 ture of 160 h.p. It is doubtful whether 

 further increase in size of channel or speed of 

 air current would advance existing knowledge 

 to an extent sufficient to outweigh the greatly 

 increased cost and other disadvantages in- 

 volved. Should it prove necessary to conduct 

 experiments on a larger scale and at higher 

 speeds, it would appear necessary to employ a 

 method in which the model is moved through 

 the air. This procedure presents various diffi- 

 culties, and the securing of even moderately 

 accurate data in this manner is at the best 

 extremely laborious. Probably the least 

 troublesome way of applying this method is by 

 installing measuring apparatus on the aero- 

 plane itself, and it seems probable that only in 

 this way can an accurate comparison be ob- 

 tained between model and full-scale condi- 

 tions. 



Improved methods of supporting the models 

 mider test have been devised for use in special 

 cases. The effect on the measured resistance 

 of the method of holding the model is often 

 surprisingly large, and without the necessary 

 care and experience in avoiding effects due to 

 interference with the air flow very large errors 

 may result. In general the difficulty is 

 greatest in measurements on forms of small 

 head resistance — e. g., aeroplane bodies and 

 airship envelopes. Probably little reliance can 



be placed on the absolute values obtained in 

 earlier measurements on airship models of 

 stream line shape, which were made to deter- 

 mine the form of least resistance, and were in 

 the main comparative. With the new methods 

 of support the possible error has been greatly 

 reduced, and when full-scale values have been 

 determined with accuracy the prediction of 

 full-scale resistance from the models will be 

 established on a satisfactory basis. 



At the Royal Aircraft Factory the measure- 

 ment of the resistance of aeroplanes in flight 

 has been continued with the object of confirm- 

 ing the model experiments, and an instrument 

 for measuring the resistance directly has been 

 developed. The distribution of pressure over 

 the wing of an aeroplane in flight has been 

 measured, and further experiments on these 

 lines are in progress. Experiments and also 

 much theoretical work have been carried out 

 on the longitudinal and lateral stability of 

 aeroplanes in flight. Measurements have also 

 been made of the disturbance of the air behind 

 a propeller, to obtain data required in the 

 design of new machines. 



SCIENTIFIC NOTES AND NEWS 



President Raymond A. Pearson, of the Iowa 

 State College, and Clarence Ousley, of the 

 Texas State College, have been appointed to 

 be assistant secretaries of agriculture. 



Dr. Ray L. Wilbur, president of Stanford 

 University and formerly professor of medi- 

 cine, has been placed in charge of the conserva- 

 tion department of the Food Administration. 



The Women's Council of Defense announces 

 the following advisory committees : Food Utili- 

 zation. — Professor R. H. Chittenden, Pro- 

 fessor Graham Lusk, Professor E. V. McCol- 

 lum. Professor L. B. Menael, Dr. C. L. Als- 

 burg. Dr. C. F. Langworthy, Professor Vernon 

 Kellogg, Dr. A. E. Taylor and President Ray 

 L. Wilbur. Public Health.—PvoieasoT W. H. 

 Welch, chairman. Dr. L. P. Ayer, Dr. Her- 

 mann M. Biggs, Dr. D. L. Edsall, Dr. Cary T. 

 Grayson, Dr. A. W. Hewlett, Dr. A. C. Jane- 

 way, Dr. F. G. Novy, Dr. R. M. Pearce and 

 Professor H. G. Wells. 



Dr. Harriet L. Hartley has been ap- 

 pointed chief of the division of child hygiene, 



