for covering the surface of the brick walls through which water seeps. One solution is composed of castile soap and water in the proportion of three-quarter pound of soap to one gallon of water, and the other solution is composed of alum and water in the proportion of half-pound of alum to 4 gallons of water. Both the soap and the alum must be thoroughly dissolved in the water before being used.

The wall should be perfectly clean and dry, and the coating should only be done when the temperature of the air is above 50 degrees F.

The first, or wash soap, should be laid on when at boiling heat with a flat brush, taking care not to form a froth on the brickwork; this should remain for 24 hours, so as to become dry and hard before the second, or alum wash, is applied. The alum wash should be applied in the same manner as the soap wash, the temperature of the alum wash when applied may be 60 or 70 degrees F., and it also should remain 24 hours before applying a second coat of soap wash. These coatings are to be repeated alternately until the walls are made impervious to water.

The alum and the soap thus combined form an insoluble compound, filling the pores of the masonry and entirely preventing the water from penetrating the walls.

TABLE SHOWING DIMENSIONS AND CAPACITY OF STANDARD WATER TANKS.

In applying this method the author of this book found that one pound of soap would cover approximately 130 square feet, and one pound of alum would cover approximately 800 square feet.

The capacity of a rectangular tank in gallons is found by multiplying its inside length, breadth and height together (to find its cubic contents), and dividing this result, if in inches, by 231, or multiplying it, if in feet, by 7.4805.

CAPACITY OF "ROUND" TANKS IN GALLONS FOR EACH FOOT IN DEPTH FROM 4 FEET TO 16 FEET IN DIAMETER,

The capacity of a "round" or cylindrical tank in gallons is found by multiplying the area of the average circle between its top and bottom by its height and dividing this result, if in inches, by 231, or multiplying it, if in feet, by 7.4805, or by multiplying the square of its average diameter by 5.87.

The capacity of an elliptical tank in gallons is found by multiplying the product of the diameters by .7854, and this by the height, and dividing their result, if in inches, by 231, or multiplying it, if in feet, by 7.4805.

Cypress lumber is the best wood for tanks, as it is more durable than pine or cedar and does not shrink or swell as much as other tank woods.

Wooden tanks are best for locations where the tank is outside and continuously exposed to the weather. Iron and steel tanks

properly kept painted are as lasting as wooden tanks, but in the average plant no care whatever is given to such a matter as the painting of the tank, and unless the metal tank is cared for, it will deteriorate more quickly than the wooden tank.

NOTE. The figures (page 182) for ring nozzle discharges will apply to any ordinary form of ring accurately enough for practical purposes, but apply especially to ordinary form of ring nozzle with square shoulder, 1-16 or 8-inch deep.

Ring nozzles with "under-cut" or "knife-edge" shoulder discharge as ordinarily constructed about 3 per cent less than quantity given in Table B, No. 1, page 182.

The degree of accuracy attained in estimating discharge through "Open Butts” is not nearly so great as may be attained by the methods of the two preceding tables-B. No. 1 and B. No. 2-by reason of greater influence of form of hydrant and differences in hose.

Pressure gauge should be attached to hydrant; if not, proper allowance must be made for loss of pressure between gauge and hydrant.

NOTE. Slight peculiarities of construction in different makes of hydrants so affect discharge from open butts of hydrants without hose that these figures apply only approximately to discharge of hydrants in general.

By using good judgment in applying corrections, as per notes page 185, results accurate to within 10 per cent may generally be obtained.

(Style A).-Ordinary Matthews (R. D. Wood & Co.'s) hydrant without independent gates, inside corner being rounded off, will probably discharge about 20 per cent. more.

(Style B).-Ordinary Chapman hydrants without independent gates have square inside corners, will probably discharge about 10 per cent more.

For the ordinary Ludlow & Lowry independent gate hydrants or chucks, figures in tables are probably nearly correct.

A

B

C

A

B

C

A

A

B

A

C | A

A

B

C

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