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tribute to the effect in one case, impede it in the other :'That water, being at rest in a funnel, and then sufferedto run through, carries little or no aix with it ; that whenmade to twirl round in the funnel, it carries a considerablequantity ; and that when it falls from a height, so as tobe in great part dashed into drops, it pushes down con-siderably more : That running through a pipe with lateralapertures, perpendicularly or obliquely, it receives airthrough the apertures, even when its motion is slow ;that when the pipe is of equal bore throughout, the quan-tity of air thus received is not great; but that, when thepipe is contracted to a certain degree in the part where theapertures are, the quantity of air is greater than that intro-duced through the funnel without air holes : That airbrought down from the top of the pipe or funnel preventsthe introduction of fresh air through the lateral holes,which in this cafe, instead of receiving more air, dischargethat already received.

Finding that the two general methods, by which airis made to pass down with a stream of water, could notbe united in one machine ; and that the pipe and funnel,with apertures for the entrance of air about or under thethroat of the funnel, have the greatest effect j I pro-ceeded to examine the most proper form and dispositionof these.

IV. Experiments and observations for regulating the fruSlureof the funnel and. pipe.

Experiments with funnels and pipes of different heights.

The water, as already observed, passing throughthe narrow throat of the funnel, is afterwards en-larged into a jet which sills the bore of a wider pipe.

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