Chap. 3 ] HYDRAULICS. 133

Maxims and Observations deduced from the foregoingTable of Experiments.

il Max. I. That the virtual or effective head being thesame, the effect will be nearly as the quantity of waterexpended.

This will appear by comparing the contents of thecolumns 4, 8, and 10, in the foregoing sets of experi-ments, as, for

Example I. taken from No. 8 and 25; namely :—

No. Virtual head. Water expended. Effect.

8 7,29 161 328

25 7,29 355 785

Now the heads being equal, if the effects be propor-tioned to the water expended, we shall have by maxim1, as 161 : 355 :: 328 : 723; but 723 falls short of 785, asit turns out in experiment, according to No. 25, by 62.The effect, therefore, of No. 25, compared with No. 8,is greater than according to the present maxim, in theratio of 14 to 13.*

The foregoing example, with four similar ones, maybeseen at one view in the following table.

• If the true maximum velocity of the wheel be ,577 of the velocity of the wa-ter, and the true maximum load be 2-3da of the whole column, as shown in Art42: then the effect will be to the power in the ratio of 100 to 38, or as 10 to 3,8,a little more then appears by the table of experiments in columns 9 and 10: thedifference is owing to the disadvantageous applies tionof the water on the wheelin the model.