1856] WRITINGS OF JOSEPH HENRY. 403 



ON ACOUSTICS APPLIED TO PUBLIC BUILDINGS. 



(Proceedings American Association Adv. of Science, vol. x, pp. 119-135.) 



Auffust 22, 1856. 



At the meeting of the American Association in 1854, I 

 gave a verbal account of the plan of a lecture-room adopted 

 for the Smithsonian Institution, with some remarks on 

 acoustics as applied to apartments intended for public 

 speaking.* At that time the room was not finished, and 

 experience had not proved the truth of the principles on 

 which the plan had been designed. Since then the room 

 has been employed two winters for courses of lectures to 

 large audiences; and I believe it is the general opinion 

 of those who have been present, that the arrangements for 

 seeing and hearing, considering the size of the apartment, 

 are entirely unexceptionable. The room has fully answered 

 all the expectations which were formed in regard to it, pre- 

 vious to its construction. The origin of the plan was as 

 follows : 



Professor Bache and myself had directed our attention to 

 the subject of acoustics as applied to buildings, and had 

 studied the peculiarities in this respect of the hall of the 

 House of Representatives, when the President of the United 

 States referred to us for examination the plans proposed by 

 Captain M. C. Meigs of the Engineer Corps, U. S. A., for the 

 rooms about to be constructed under his direction in the new 

 wings of the Capitol. After visiting with Captain Meigs the 

 principal halls and churches of the cities of Philadelphia, 

 New York, and Boston, we reported favorably on the gen- 

 eral plans proposed by him, and which were subsequently 

 adopted. 



The facts we have collected on this subject may be referred 

 to a few well-established principles of acoustics, which have 



* [" On the Arrangement of Lecture Rooms, with reference to Sound and 

 Sight." — Proceedings of the American Association for the Advancement of 

 Science, May, 1854 ; vol. viii, p. 106. Only the title published.] 



