MR. RENNIE ON THE FRICTION AND RESISTANCE OF FLUIDS. 437 
Table IX. 
Experiments on the Quantities of Water discharged by Leaden Pipes \ inch 
bore, but of different lengths from one foot to thirty feet in length. 
Glass tubes 
1 meh long, 
J inch diam. 
Brass 
orifice 
§ diam. 
1 foot 
long. 
3 ft. 9 in. 
7 ft. 6 in. 
1 1 ft.3 in. 
15 ft. 
30 ft. 
Remarks. 
feet. 
4 
3 
2 
1 
seconds. 
55 
63 
77 
110 
seconds. 
73 
83 
104 
144 
seconds. 
55 
63 
93 
133 
seconds. 
78 
92 
113 
170 
seconds. 
102 
120 
151 
226 
seconds. 
122 
145 
184 
278 
seconds. 
143 
164 
208 
312 
seconds. 
203 
240 
303 
450 
The ratio of discharge by glass tubes with 
pipes of 30 feet long, is as 1 : 4 \ , 
Ditto with brass orifices, is as 1 : 3 J near - V- 
Conclusions on Pipes of different lengths. 
That the expenditures of water by pipes of equal diameters but of unequal lengths and under different 
altitudes, are nearly as follow. 
The length being as 30 to 1, the expenditures are as 3.7 to 1 
Do. ... 8 to 1 ... do. . . . 2.6 to 1 
Do. ... 4 to 1 ... do. . . . 2.0 to 1 
Do. ... 2 to 1 ... do. ... 1 .4 to 1 
The discharges by glass and leaden tubes are nearly alike. The length of a pipe may be increased 
from 3 to 4 feet without diminishing the discharge as compared with the plate orifices. 
