THE COMPONENT PRESSURE RECORDER. 53 



were replaced by othev.s backed with strips of brass, which gave the planes the 

 desired weight, and also contributed the necessary stitfness. The latter planes 

 are made of pine i of an inch thick, with square-cut edges. The brass strip 

 is a piece of hard-rolled brass running the whole length of the plane, and about 

 2 inches wide. In the 24 and 30 inch planes the middle of the strips was bent 

 slightly outwai-d — /. e., " corrugated " — for greater stiftness. 



The experiments were made in two series. The first series was made on 

 eight days, from September 29 to October 9, inclusive, and consisted in deter- 

 mining the soaring speeds and corresponding resistances of the above-described 

 planes set at angles from 2° to 30°, and the horizontal pressure on the planes 

 when set at 90° — that is, normal to the line of advance. In all, 95 complete 

 observations were taken. 



The following is an example of the original I'ecord made in these observa- 

 tions, extracted from the note book for October 8 : 



Experiments with Component Pressure Recorder to determine horizontal pressures at soaring speeds. 



October 8, 1890. 



F. W. Very, Conducting experiments ; Joseph Ludewig, Regulating engine. 



Barometer, 736.6; temperature, 15° C. ; air meter at 10:30 a. m., 1,509,500; air meter at 

 3:20 p. m., 1,500,400; 30 x 4.8 inch plane; weight, 500 grammes ; spring No. 2. 



* The use of an English scale instead of a metric one in measuring the spring extensions introduces a lack 

 of harmony in the system of units employed that is not to be recommended ; but since this is a record of the 

 original observations, the measurements as actually made are fiithfnlly presented. 



