C 77 ) 
VI. An Account of federal Experments concerning 
the (limning of Water in ^ipes, as it is retarded 
by FriBion and intermixed Air^ fome of which 
were made before the ^oyal Society on Thurfday 
the ^th of May, 1726. With a Defcription of 
a new Machine, tvhereby Fipes may be clear d of 
Air, as the Water runs along, without Stand-Fipes, 
or the help of any Hand, the J. T 
Defaguliers, LL. D. F. R. S. 
H aving found by feveral Experiments in 
fmall, that thro’ a long Pipe, Water wou’J 
not be difcharg’d in the fame Quantity by a great 
deal, as it wou’d be thro’ a fhorter of tlie fame Bore, 
the Orifice being at the fame Depth under the Sur- 
face of the Water in a Refervoir; I made an Experi- 
ment upon a Pipe above looc Yards in length, and 
of 1 1 Inch Bore, at his Grace the Duke of Chandos\ 
Houfe at Cannons and found that the Quantity of 
Water given was much lefs (I think -J? lefs) than it 
ought to have been according to Mon f. Mariottds 
Rules and that fomething more than the Fridion, 
on Account of the Length of the Pipe, had retarded 
the Watery which I found fince to be Air confin’d in 
the eminent Parts of the Pipe. A full Account of 
this Experiment I publilh’d in my Notes upon Ma- 
rhttes Mouvement des Eaux, in the EngUJh I'ranlla- 
tion, fome Years ago. 
Confidering this Matter again lately, I made the 
following Experiment. Fig. i. A is a Veffel contain- 
ing a Cubic Foot in the Jnfide, and always -kept full 
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