M'Quisten's Interim Report. 201 



In both cases about ^^ of an inch less by the formula than was actu- 

 ally found necessary. 



Now, to show how perfectly justifiable the adoption of the higher co- 

 efficient -006, is in this case, if we determine the discharge using the 

 complete formula, viz. — 



A— -023 0' = -003 -5^ Q'-« 



We can by the above deduction of the diameter d = 1*6544 deter- 

 mine c ^ 16-5 nearly 



h — -023 c* = 3-74 



r ♦" = -1^ Q' " from which we have 



r = -86 + 01 = -87 = (i = 1*74 

 Pipe 1-6875 



Difference, 00525 



Formula in excess of experiment. 



A mean between the two results of the formulas is 1.69, a result 

 which would naturally have been chosen, had the case been to be put 

 in practice at this moment. 



Interim Report hy the Subscriber, Peter M'Quisten, Civil Engineer 

 in Glasgow, relative to agreement between the Proprietors of House- 

 hill, and Messrs. John Wilson & Sons. 



Glasgow, Zd April, 1837. 



Gentlemen, — I have your letter of the 27th March, 1837, with ex- 

 cerpt of agreement between Proprietors of Househill and Messrs. John 

 Wilson & Sons, dated 16th March, 1837, and I beg leave to report, 

 that a lead pipe eight feet long, laid horizontal, and having a pressure 

 of water upon it of ten feet perpendicular, will vent a discharge ex- 

 actly one hundred imperial gallons of water per minute, by making 

 the pipe one inch and eleven sixteenth parts of an inch in diameter. 



I have also to report, that a lead pipe eight feet long, laid horizon- 

 tal, and having a pressure of water upon it of ten feet perpendicular, 

 will vent or discharge exactly eighty imperial gallons of water per 

 minute, by making the pipe one inch and nine sixteenth parts of an 

 inch in diameter. 



I am, Gentlemen, 



Your very obed. Servant, 

 (Signed) PETER M'QUISTEN. 



To Robert Wylie, Es-q., Writer, Paislev, 



Agent for the Proprietors of Househill, 

 and Alexander Gibson, Esq. Writer, 

 Paislev, 



Agent for Messrs. John Wilson & Sons. 



No. 10. 5 



