AMERICAN INSTITUTE. 377 



the pipes are filled with steam, and the air then passes into ventilators, or 

 through perforations in the floors. I think the method adopted is very 

 excellent, and seems to give great satisfaction. 



Mr. John Johnson spoke of the want of practical thought, in the arrange- 

 ment of ventilators. 



^ahle containing the Velocity and Force of the Wind. 



Pependicular 



/—Velocity of the wind.— s force on 1 foot 



Miles in Feet in area in pounds 



1 hour. a second. avoirdupoia. 



Hardly perceptible. 

 Just perceptible. 



Gentle, pleasant wind. 



^ > Pleasant, brisk gale. 



Very brisk. 



High wind. 



Very high wind. 



A storm, or tempest. 

 Great storm, 

 A hurricane. 



A hurricane that tears up trees, and 

 carries buildings before it. 

 For ventilation in mines, the air is moved at about five miles per 

 hour. 



On motion of Mr, Stetson, the subject was continued for the next meet- 

 ing, and hoping some practical men will furnish estimates of relative cost 

 of warming and ventilation. 



Adjourned. JOHN W, CHAMBERS, Sec'y pro tern. 



June 23, 1858. 



Present- — Messrs, Backus, Cohen, Johnson, Godwin, Seeley, Disturnell, 

 Leonard, Chambers, TJpfield, of Lancaster, Ohio ; Mr, Maine and others — ■ 

 24 members in all. 



The regular chairman, Thomas B. Stillman, being absent, Samuel D. 

 Backus, was chosen chairman pro tern, Henry Meigs, Secretary. 



Mr. Cohen moved that our meetings during summer, be held at 5 o'clock 

 P. M., and that when we adjourn, that it be until after the fair, unless 

 sooner called by the Chairman. 



Mr. Leonard seconded the motion, which was carried unanimously. 



The Chairman called up miscellaneous business. None being then 

 ofi'ered, he stated some remarks he had made on the cause of exfoliation of 

 paint from brick walls, even from often painted, old hard brick walls. Waa 

 it uniformly so ? What is the rationale of it ? 



Mr. Johnson inclined to think it due to the action of frost upon the 



