416 



FOUHTH REPORT — 1834. 



locks and sluices, &c. ; or when the motions are rendered com- 

 plicated by a system of pipes, as in water-works. The influence 

 of friction* and adhesion was briefly alluded to. Friction was 

 stated to have been found to be nearly independent of pressure 

 and surface, being the same when the fluid was made to run over 

 different kinds of surfaces, such as glass, wood, and metals, 

 &c.; and with regard to the velocity, resistances were stated to 

 be as the squares of the velocities at moderate inclinations. 

 Lastly, as to adhesion, reference was made to the experiments 

 of Coulomb and others to determine the molecular action of 

 fluids. 



The theory of the motions of canals and rivers is founded on 

 the following axioms : 



1st, That the fluidity of the water, which obliges it to main- 

 tain a perfectly level surface in any close vessel containing it, 

 allows it to move with the utmost faciHty in any direction, 

 under the influence of external impulse or gi'avity; 



2ndly, That motion cannot take place in an artificial channel 

 without an inclination in the surface ; 



* From the following experiments with which I have been favoured by 

 William Tierney Clarke, Esq. of the West Middlesex AVater-works, the friction 

 and resistance of the pipes to the free motion of the water through them have 

 been found to be between one fourth and one fifth of the total height of the 

 column. 



Table showing the result of Experiments made at the West Middlesex Water- 

 works upon work performed by the 64-inch cjdinder Engine by Messrs. 

 Boulton, Watt, and Co., working with coal as stated below, to BaiTow Hill 

 Reservoir, being an elevation of 188 feet above low water of the river 

 Thames, and working through the 15-inch, 12-inch, and 9-inch Mains. 



1833. Wylam Moor.. 



1834. Holly well Main 



— Ditto 



— Ditto 



— Wylam Moor.. 



Pounds raised I 

 foot high percwt. 

 of coal consumed, 

 exclusive of fric- 

 tion and obstruc- 

 tions in pipes, cal- 

 culatedatl88feet. 



nS lbs. 



41,406,202 

 44,625,373 

 45,094,274 

 44,338,876 

 41,046,265 



I 1 ounds raiscdj Pounds raised 1 

 il foot high pcrfoot high percwt. 

 bushelof coal con-'ofcoal consumed, 

 sumed, exclusive including all re- 

 of friction and sistancc in pipes, 

 obstructions in'calculated at 42 

 pipes, calculated feet — equal to 230 

 at 188 feet. feet head. 



84 lbs. 



31,054,651 

 33,469,029 

 33,820,705 

 33,254,157 

 30,784,698 



112 lbs. 



50,656,523 

 54-594-87I 

 55,169,560 

 54,242,241 

 50,213,782 



Pounds raised 

 1 foot high pel 

 bushel of coal con 

 sumed, including 

 all resistance in 

 pipes, calculated 

 at 42 feet— equal 

 to 230 feet head 

 84 lbs. 



37,992,391 

 40,946,153 

 41,377,170 

 40,681,680 

 37,660,33 



