48 



SCIENCE 



[N. S. Vol. LIII. No. 1359 



down at the top to a moutli Ij" in diameter, 

 the fundamental appears at once (ss' across 

 the middle). If now the distance so is de- 

 creased, the overtone will appear loudly. It 

 is not the fifth above, however, but the octave, 

 itself. As the kinematics of the stationary 

 waves are given, the overtone belongs to an 

 original wave of 3/2 longer wave-length than 

 the fundamental. 



Figure 3, 4, is another form of blower 

 adapted for wide pipes, made of square brass 

 tubing pp'. One edge of this has been filed 

 down until a rift cc' may be cut with the fine 

 blade of a knife. The strip ss' here advan- 

 tageously covers the pipe T to be tested; or 

 the hands may be used to cover projecting 

 sides of T. The form. Fig. 3, with an alter- 

 native influx P', may be duplicated, affording 

 two opposed rifts and strips. Tin cups, fun- 

 nels, etc., as well as long wide tubes respond 

 to it sonorously. 



Interference. — This experiment succeeded 

 beautifully with the strip ss' of the blower, 

 Fig. 1, placed between- two coaxial pipes, P 

 and P' (Fig. 2), each about 10 cm. long and 

 2 cm. in diameter (for instance) and closed at 

 the outer end. Either pipe alone sounds 

 vigorously when in position and actuated by 

 the blower. With the two together there is a 

 mere siffling, the wave running from end to 

 end of the (virtually) double closed pipe PP'. 

 Nevertheless, there is abundant room at mm 

 for the escape of sound; indeed, one pipe, P, 

 for instance, may even be placed at right 

 angles to the other, leaving a wide open space, 

 and still almost the whole compression of one 

 pipe is alternatingly absorbed by the other. 

 The experiment is an excellent illustration 

 of the reversal of spectrum lines. 



The nodes here are respectively dense and 

 rare; i.e., always opposite in the two pipes. 

 Hence, the interference. In the cross pipe 

 used heretofore, the nodes were necessarily 

 identical in sign, and, therefore, gave marked 

 reenforcement. The same will be true if the 

 pipes P, P' are each open at the further end. 



Carl Baeus 

 Brown University, 

 Providence, E. I. 



THE WESTERN DIVISION OF THE 



AMERICAN ASSOCIATION FOR 



THE ADVANCEMENT OF 



SCIENCE 



The first Annual Meeting of the new 

 Southwestern Division of the American As- 

 sociation for the Advancement of Science 

 was held in El Paso, Texas, on Thursday, 

 Friday and Saturday, December 2, 3 and 4, 

 1920. The officers at the meeting, elected at 

 the Organization Meeting in April, 1920, 

 were: President, Dr. Edgar L. Hewett, of 

 Santa Fe; Vice-president and chairman of the 

 Executive Committee, Dr. E. C. Prentiss, El 

 Paso; Secretary-Treasurer, Dr. A. E. Doug- 

 lass, Tueson. The Executive Committee in- 

 cluded also Dr. John D. Clark, Albuquerque, 

 Mr. A. L. Flagg, Phoenix, Professor Fabian 

 Garcia, Mesilla Park, Mr. Arthur Notman, 

 Bisbee, Mr. Robert S. Trumbull, El Paso, 

 Professor Milton Updegraff, Prescott and Dr. 

 Chas. T. Vorhies, Tucson. Dr. D. T. Mac- 

 Dougal was chairman of the organization 

 committee. The affiliated societies partici- 

 pating in this meeting were, The American 

 Association of Engineers, Southwestern Dis- 

 trict, The Medical and Surgical Association 

 of the Southwest, The 'New Mexico Archaeo- 

 logical Society. The Sante Fe Society of the 

 Archseological Institute, The Mexico Medical 

 Society and the El Paso County Medical 

 Society. The trustees of Temple Mount 

 Sinai loaned their very convenient rooms and 

 auditorium for two days. The El Paso High 

 School did the same for the final day and pro- 

 vided lunch. The Ad Club of El Paso enter- 

 tained the members at lunch; the El Paso 

 County Medical Society were hosts at a recep- 

 tion and dance at the Toltec Club. Excur- 

 sions to points of interests were provided. 



An important event of the meeting was the 

 session on Friday afternoon in the Mexican 

 City of Juarez. As the members entered the 

 Juarez theater, they were received with the 

 strains of the " Star Spangled Banner," 

 played by a Mexican military band. This 

 was followed by the Mexican National 



