678 REPORTS OF THE BUILDING COMMITTEE. 



August 17, 1847. 



Gentlemen : Several details connected with the arrangement of the laboratory of 

 of the Smithsonian Institution have recently occurred to me, or been suggested by 

 conversation with gentlemen experienced in chemical manipulation. I place them 

 at your disposal, in case you may see lit to adopt all or any of them. 



I advise that the sliding doors between the laboratory and lecture-room be of sheet 

 copper, blackened, so that they may serve as black boards for the purpose of illus- 

 tration. 



Pulleys in the ceiling of the laboratory, behind the lecturer's table, will be found 

 very convenient to suspend illustrations, so that they can be raised or lowered. 

 Black boards of blackened sheet copper or iron, in nests or sets to slide one behind 

 the other, will be found extremely useful to the lecturer, thus suspended by pulleys. 



The floor of the laboratory may advantageously be covered with thick sheet zinc. 



The roof of the laboratory is best covered with slate, as the rain-water caught 

 from a slate roof is purer than from a metal one. 



The tops of all the tables in the laboratory, including the narrow tables below the 

 shelving, should be of serpentine, and from one to two inches thick. Serpentine can 

 be procured from Proctorsville, Vermont. Even the tops of the tables to hold the 

 balances are best of this material. It is not acted upon by acids ; that is, the 

 Vermont variety. 



The flues of the furnace over the hot air chambers should be of half-inch soap- 

 stone slabs. 



There should be in the basement, gasometers for hydrogen or carburetted hydrogen 

 — very convenient in organic analyses. 



The air should be admitted above the ash-pits in the cellar ; for if it be not, the 

 ashes blow up with the draught. 



The furnace flues should all be smoothly plastered inside, especially those of fur- 

 naces to raise high temperature. For such furnaces Dr. Jackson, of Boston, recom- 

 mends flues tapering from below upwards, the larger flues being a little over 12 inches 

 iD the basement, and tapering to nine inches at top ; and the area at top being 

 somewhat greater than that of the flue throat next the furnace. He is of opinion 

 that by this form of flue, the lateral currents of cool air that usually pass down 

 chimneys are prevented, and thus all the cold air must pass through the furnace. I 

 have tried the plan, and they draw well. 



It is unnecessary to line the flues with fire-brick, except at the throat leading from 

 the furnace. 



Every table, both in the laboratory and in the working laboratory, should be 

 furnished with a blast pipe, proceeding either from a large bellows in the basement, 

 or a small bellows fixed under the table, or a condensing syringe. 



If, in the course of the erection of the Smithsonian laboratory, I can be of any 

 service in furnishing further details, I shall do so with pleasure, if written to on the 

 subject; and to avoid misapprehension, I may add, without any charge to the 

 Institution. 



I regret that my occupation as geologist of "Wisconsin is likely to take me to so 

 great a distance from your city, that I shall have little chance to aid by personal 

 supervision, as otherwise I should have been happy to do. 



Eespectfully submitted, by DAVID DALE OWEN. 



To the Building Committee of the Smithsonian Institution. 



On motion, the above communication was referred to the architect of the Insti- 

 tution. 



Mr. Kenwick, the architect, appeared before the committee, and stated that it was 

 probable that plates of Grace church, and of Trinity, could be procured, if he (the 

 architect) were authorized, by resolution of the committee, to make application for 

 the same. 



On motion of Mr. Owen, the following preamble and resolution were adopted : 



Whereas it has been represented to this committee that some members of the vestry 

 of Trinity church, New York, have liberally expressed their willingness to furnish 

 to the Smithsonian Institution a plate on steel or copper, containing a perspective 

 view of Trinity church, to be printed in the forthcoming volume on Public Archi- 

 tecture, about to be published by this committee ; Therefore, 



Resolved, That Mr. James Kenwick, architect of the Smithsonian Institution, be 

 and is hereby authorized, on behalf of the said Institution, to state to the said vestry 

 that if they decide to furnish said plate, it will be accompanied in the said volume 

 with a description Of Trinity church, as exhibiting the best example in the United 



