156 



SCIENCE 



[N. S. Vol. LIV. No. 1390 



the density of air contained would tend to in- 

 crease and the cylinder fall for this reason 

 also. But the present experiment is relatively 

 too crude to show this. For the content of 

 the cylinder e (6 cm. long) may be taken 

 as 33 milligrams of air. The forces registered 

 by the pinhole valve in experiments with reso- 

 nators did not exceed dp \ p^S'X. 10"*. Thus 

 the increment of weight of e is but 10"^ dyne, 

 which would lower the index of the torsion 

 balance only .3 mm. 



3. Finally let the closed cylinder e be re- 

 placed by the cylinder r open below and 

 capable of entering the pipe p. Let the length 

 of r be such that the open cylinder is in 

 resonance with p. Then the conditions of the 

 experiment are obviously improved (though 

 not as much so in the experiment as antici- 

 pated^) ; but the results will still be the same 

 in character. The open end of r will tend to 

 enter the sounding pipe p ; wMch is the 

 equivalent of the Mayer-Dvorak experiment, 

 here exhibited without any " neck " effect and 

 without air currents. 



4. I may add a comparison of the pin-hole 

 compression observed in the given pipe (2.6 

 cm. diameter and 13 cm. long) when sounding 

 loudly (i.e., when resistance in the telephone 

 circuit has been reduced as much as possible) 

 and the compression observed in the oi)en 

 organ pipe of the standard form on the inter- 

 ferometer. The embouchured organ pipe, 

 tested on the interferometer,^ showed for the 

 maximum compression dp\ p^ 10"* X 14 in 

 case of a moderately loud note. The telephone 

 closed pipe, tested with the pin-hole valve at 

 the end of a quill tube thrust well within, 

 gave a displacement of 20 fringes with 2,000 

 ohms in circuit. This is equivalent to a pres- 

 sure increment of .0120 cm. of mercury when 

 but 100 ohms are in circuit, as was approxi- 

 mately the case in the experiments of this 

 paragraph. Thus in case of the probe 

 dp I p = 1.6 X 10"*- Reservoirs at the U-tube 

 of different volumes showed the same quanti- 



1 On varnishing the paper resonator to stiffen it, 

 forces above 2 dynes per em.s were directly meas- 

 ured. 



2 Science, LII., p. 47. 



tative result. The increment (compression) 

 does not quite vanish even in the plane of the 

 mouth of p, but a little beyond. The ratio of 

 the two compressions is thus 87; but while the 

 interferometer direct gives a fringe displace- 

 ment rarely exceeding 1, the pin-hole valve, 

 under like conditions, will give fringe dis- 

 placements easily several hundred times larger, 

 depending on the degree of approach to the 

 critical diameter of the pin hole. 



Carl Barus 

 Bkown TJniveksity, Pkovidencb, R. I. 



THE KENTUCKY ACADEMY OF 

 SCIENCE 



The Kentucky Academy of Science held its 

 eighth annual meeting on May 14th at the Uni- 

 versity of Kentucky, Lexington. The meeting 

 was called to order at 9:30 o'clock by President 

 Coolidge. 



The secretary's report showed 127 members, in- 

 cluding 44 national members, 55 local members, 

 21 corresponding members and 7 honorary mem- 

 bers. These represent 37 different lines of ac- 

 tivity of which chemistry leads with 26 members. 

 Twenty-one new members were elected. 



The report of the committee on legislation pro- 

 posed a large program to be worked for, including 

 a state appropriation for the support of the acad- 

 emy; awarding prizes for research; increased ap- 

 propriations for completing the topographical map 

 of the state and soil surveys; a natural history 

 survey of the state and the establishment of a 

 natural history museum ; increase in the teaching of 

 science in the high schools; the preservation of the 

 records of drilled wells; the setting aside of areas 

 for preserving natural conditions and the endorse- 

 ment of the law now before Congress to make 

 Mammoth Cave and its environs a national park. 

 This report was adopted. 



The officers elected were: 



President, George D. Smith, State Normal School, 

 Richmond, Ky. 



Vice-president, Lucien Beckner, Winchester, Ky. 



Secretary, A. M. Peter, Experiment Station, Lex- 

 ington, Ky. 



Treasurer, Charles A. Shull, University of Ken- 

 tucky, Lexington, Ky. 



Member of Publications Committee, D. W. Mar- 

 tin, Georgetown College, Georgetown, Ky. 



Representative in the Council of the A. A. A. S., 

 A. M. Peter. 



The program included an address by Dr. Henry 



