1878.] 4 



granted and the Engineers' Club placed among the Society's 

 correspondents to receive the Proceedings from the begin- 

 ning of 1878 onward. 



Letters requesting the supply of deficiencies in the series 

 of the Society's publications were received from Triibner & 

 Co., from the Boston Public Library, and the Naval Ob- 

 servatory, and were referred to the Librarian for action. 



A request for subscription to the " American Catalogue," 

 dated September 17, iSTew York, 87 Park Row, was referred 

 to the Librarian to consider and report.- 



A letter was received from S. Guerrier, Emporia, Kansas, 

 September 9, asking the worth of an old Bible (1602) de- 

 scribed by its owner. 



The committee to which was referred Prof. Haldernan's 

 plates and descriptions of prehistoric remains in the cave 

 near Chicques rock in Lancaster Co., Pennsylvania, reported 

 in favor of their publication in the Transactions of the 

 Society. On motion the report was accepted and the com- 

 mittee discharged. On motion the publication was or- 

 dered. 



The Committee on Finance was requested to inquire into 

 and report upon the expediency of publishing the two memoirs 

 presented at recent meetings by Dr. Lautenbach, of Geneva, 

 Switzerland.* 



Dr. Konig exhibited and described a piece of chemical 

 apparatus which he invented for the purpose of applying the 

 use of sliding glass wedges, colored and transparent, and 

 empirically graduated, to the optical extinction of the colors, 

 simple or compound, of the blowpipe beads of the chromatic 

 metals, ground to a given thickness and rendered trans- 

 parent by a coating of balsam. The use of the glass wedge 

 has been known i but this use of complimentary colors for 

 producing the extinction of a given color, and for thus ob- 

 taining the exact degree on a scale marking the percentage 

 of metallic elements contained in the bead, is new, and, as 



: See Minute Book, Oct. 18, 1878. 



