320 PROCEEDINGS OF THE AMERICAN ACADEMY 



Time in Velocity per 

 Seconds. Second. 



"■Exp. 21.* Cone and plate similar to last; base 

 2.5 inches in diameter ; height .62 inch ; inclination of 

 side to base 45° (see fig. 9), 



" Same cone without plate, ..... 



" Exp. 22. Saint-Martin's cone without the cap ; 

 to the upper surface and around the opening a hollow 

 truncated cone is fitted ; height .62 inch ; angle of 

 sides 42° ; larger base of the frustum upward, . 24.0 2.21 



"-Exp. 23. Cone used in Exp. 21, with a hollow 

 truncated cone, .37 inch high, and angle of sides 42°, 

 fitted as in last experiment, ..... 24.5 2.16 



" Exp. 24. Cone ; angle of sides with base 48° ; 

 with hollow truncated cone, as in last experiment, . 25.0 2.12 



" Exp. 25. Cone ; diameter of lower base 2.5 

 inches ; diameter of upper base 1.6 inches ; height 

 .55 inch ; internal diameter at lower base 1.25 inches, 

 and diverging to 1.6 inches at upper base, . . 25.5 2.08 



" Exp. 26. Cone similar to that used in Exp. 21, 

 with a flat plate, as recommended by Cisalpin (see 

 fig. 6), .7 inch above top of cone ; diameter equal to 

 that of base of cone ; on under surface of the plate a 

 hollow cone .37 inch in height, lesser base downwards, 25.0 2.12 



" Exp. 27. Square block representing a chimney ; 

 flue Ij- inches in diameter ; sides 2 inches ; height 4 

 inches ; one side towards the blast, . . . 33.5 1.57 

 " Same, with corner towards the blast, . . . 35.5 1.49 

 " Same, with a small cone .5 inch high ; angle of 

 side 63° ; side to the blast, 37.5 1.425 



" Exp. 28. Same block, with its plane upper sur- 

 face inclined towards the blast, at an angle of 3° with 

 the horizon, ....... 



" Same, at an angle of 10° with horizon, ' . 



(( (( (( OQ*^ " " 



* Dimensions of the original of this model : — diameter of flue 8 inches ; diam- 

 eter of cone at base 16 inches ; height 4 inches ; diameter of plate 16 inches, and 

 4 inches above top of cone. 



