Sanitary work in the smaller towns and in villages. In three parts. Part I. Some of the more common forms of nuisance, and their remedies. Part II. Drainage. Part III. Water-supply. / by Charles Slagg.

  • Slagg, Charles.
Date:
1876
Catalogue details

Licence: Public Domain Mark

Credit: Sanitary work in the smaller towns and in villages. In three parts. Part I. Some of the more common forms of nuisance, and their remedies. Part II. Drainage. Part III. Water-supply. / by Charles Slagg. Source: Wellcome Collection.

Provider: This material has been provided by London School of Hygiene & Tropical Medicine Library & Archives Service. The original may be consulted at London School of Hygiene & Tropical Medicine Library & Archives Service.

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    were treating of hydraulics in general we should see how, by the appliance of wing-boards above the weii', or, in the case of orifices wholly below the surface, by adjutages below the opening, the discharge is increased to almost the whole quantity indicated by theory, but those are not the circumstances under which water is gauged in ordinary practice. In calculating the quantity discharged the depth enters twice into consideration. In the first place it is an element of the sectional area of the stream, and in the second of the velocity. The sectional area is as the depth, and the velocity as the square root of the depth. The cubic quantity discharged is therefore as d V d or as V d^. If the quantity be taken in cubic feet per second per foot in length of the weir it is 5'35 V d^ by the theory of falling bodies, the depth being measured in feet; and if it be taken in cubic feet per minute it is 321 \/d''^ per foot in length of the weii'. But it is more convenient to measure the depth in inches, in which case the constant 321 must be divided by the square root of the cube of 12, or V 1728 = 321 41*57, and ^ = 7'72, the constant of the theoretical 41-57 quantity per foot in length of weir when the depth is measm'ed in inches and the quantitj' in cubic feet per minute. If we put I = the length of the weii' in feet, this quantity would be 7'72 I \/ d'^. But practice has proved that not only is the actual discharge less than that of theory imder every con- dition of a weir, but that the constant multiplier varies with both the length and the depth. By measming, in large tanks the actual quantities discharged under I