168 PROCEEDINGS. 



WEDNESDAY, SEPTEMBER 3, 1890. 



Dr. Leibius, m.a., f.c.s., President, in the Chair. 



Fifty -five members and twenty visitors were present. 



The minutes of the last meeting were read and confirmed. 



The Certificates of five new candidates were read for the 

 second time, and of three for the first time. 



In the absence of the author, the Hon. Secretary (Mr. Kyngdon) 

 read a continuation of a paper by Baron Ferdinand von Mueller, 

 k.c.m.g., m. &Ph.D., f.r.s., " Record of hitherto undescribed plants 

 from Arnheim's Land." 



Prof. Warren read a paper " On the application of the results 

 of testing Australian Timbers to the design and construction of 

 timber structures." 



Some remarks were made by Messrs. J. Trevor Jones and O. 

 Burge when the Chairman announced that the discussion upon 

 Prof. Warren's paper would be postponed to the next meeting, 

 in order that the paper and diagrams might be printed and cir- 

 culated amongst those members interested in the subject, previous 

 to the discussion taking place 



The thanks of the Society were accorded to the authors for 

 their valuable papers. 



Mr. J. A. Pollock on behalf of Prof. Threlfall exhibited an 

 enlargement for lecture purposes, of a negative of Fresnel's Inter- 

 ference bands. The light used in the production of the bands 

 was that of the electric arc rendered nearly homogeneous by 

 allowing it to pass through a cell containing a solution of strong 

 nitrate of copper and chromic acid. The bands were formed by 

 passing a filtered light through a biprism. 



Mr. C. L. Garland, m.l.a. exhibited and described one of Edison's 

 latest perfected Phonographs, he said that he thought his task in 

 explaining the phonograph would be an easy one, seeing that he 

 was speaking to a number of scientific gentlemen. For that 

 reason he did not need to go into the question of the relationship 

 of sound to the human ear. He mentioned that some twelve years 

 ago Mr. Edison suddenly hit upon the the discovery that the 

 human voice could be stored up and reproduced by means of a 

 diaphragm attached to a ball point which travelled over indenta- 

 tions made in tinfoil. An old tinfoil phonograph had, he believed 

 been exhibited some years ago in that very hall. Eight or nine 

 years elapsed after the manufacture of that article, during which 



