129 [ 23 ] 



On motion of Mr, Owen, it was 

 Resolved, Thai the superintendent be authorized to contrar«,t for the 

 engraving of said plate, at an expense not exceeding fifteen dollars. 

 And, on motion, the conunittee adjourned. 



THIRTIETH MEETING— April 19, 184T. 



Present, Messrs. Seaton and Owen. 



'I'he chairman laid before the committee, from Dr. Owen, the following 

 communication relative to details of arrangements in the laboratory : 



August 17, 1847. 



Gkntlemf.n: Several details connected with the arrangement of the 

 laboratory of the Smithsonian Institution have recently occurred to me, 

 or been suggested by conversation with gentlemen experienced in chemi- 

 cal manipulation. 1 place them at your disposal, in case you may see fit 

 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 illustration. 



Fnlleys in the ceihng 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 hiboTatory 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 soapstone slabs. 



Tiiere should be in the basement, gasometers for hydrogen or car- 

 buretted hydrogen — very convenient in organic analyses. 



The air should be admitted above the ashpits in the cellar; for if it be 

 not, the ashes blow up with the draught. 



The furnace flues should all be smoothly plastered inside, espe'^ially 

 those of furnaces to raise high temperature. For such furnaces Dr. Jack- 

 son, of Boston, recommends flues tapering from below upwards, the larger 

 flues being a little over 12 inches in 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 nuist 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^ 



9 



