498 AUSTIN: RESONANCE MEASUREMENTS 



its activities local. It was incorporated April 8, 1893, and 

 issued from Washington Annual Proceedings and a Monthly- 

 Journal, but the club apparently went out of existence the 

 latter part of 1899. Numerous botanical papers were pubHshed 

 but none relating specifically to local botany. 



FeeUng the need of a flora of the District with notes and keys 

 that could be used by local amateurs and by the school teachers 

 and children, Mr. C. L. Pollard issued a prospectus with sample 

 pages of such a flora about 1896, and while many of the fami- 

 lies were subsequently written up the project was never com- 

 pleted. In continuation of this idea a number of the systematists 

 in the Botanical Society of Washington formed a Seminar for 

 discussing local flora work early in 1906, and as a basis for such 

 work the writer prepared and issued (letterpress copy) in June 

 of that year a compilation of all reported occurrences of plants 

 in the District together with such additions as members of the 

 Seminar could supply. The cards upon which the hst was 

 based were distributed by famihes to various local botanists 

 who were to prepare these famihes. The work for the next few 

 years was of a desultory character until 1912 when bi-monthly 

 Seminar meetings for work on the local flora were begun at the 

 instigation of Prof. A. S. Hitchcock, and have been held continu- 

 ously up to the present time. Assignments of families were 

 made to about thirty botanists, but pressure of official duties has 

 resulted in the withdrawal of a few before the completion of the 

 work. 



RADIOTELEGRAPHY. — Resonance measurements in radio- 

 telegraphy with the oscillating audion. L. W. Austin, U. S. 

 Naval Radiotelegraphic Laboratory. 



For purposes of rough tuning, many workers have doubtless 

 made use of the click heard in the telephones of an oscillating 

 audion circuit when it is brought into resonance with another 

 circuit at proper couphng. As the resonance click has appar- 

 ently not been mentioned in any of the pubhcations on radio- 

 frequency measurements, it seems probable that it is not gener- 

 ally known that this chck offers by far the quickest and simplest 



