The secretary presented letters from Prof. ~'~. Mascart, of Paris, Col. Turrettini, of Geneva, and Prof. W. Cawthorne Unwin, of London, accepting, election as honorary members of the Institute; from General A. \V. Greely, Chief Signal Ot~icer, in response to the official letter of the secretary transmitting the thanks of the Institute, expressing gratification on behalf of himself, Captain H. H. C. Dunwoody, and Sergeant T. F. Townsend, of the Signal Office, that the policy of the service has merited the ~pprobation of the Institute, a~d the assurance of continued co-operation in the work of the State Weather Service; and from M. W. Grosseteste, Engineer of Mulhouse, presenting to the Institute a copy of a medal and a pamphlet prepared as a manifestation of honor to the late M. Gustav Adolph Hirn. In reference to the last communication, the gift was accepted with thanks, and the secretary was directed to acknowledge the courtesy of M. Grosseteste and his colleagues, and to convey to him and them a suitable expression of the high appreciation with which the members of the Franklin Institute esteem the scientific work of M. tqirn, which has added so much to our knowledge of the action of heat in the steam engine.
In the absence of Mr. F. Lynwood Garrison, the secretary presented a brief abstract of his paper announced for the evening, on the manufacture of tin-plate. (Referred for publication.)
Mr. Wm. B. LeVan read a paper, illustrated by numerous diagrams and specimens, on the proper method of making joints in steam-boilers. The paper was discussed by Messrs. Fullerton, Christie, Wiegand and the author.