Popular Science Monthly
��Developing a Long Photographic Film in One Piece
THE device illustrated is useful in developing kodak films. A long film may be developed and at the same time a sufficient portion of it can be watched during de- velopment. Mount a film- holder of special shape on a base having suitable legs, together with a cen- tral rod and handle. Unwind a roll of film and remove the paper backing. Wind the film around the upper part of the spiral holder, one end being secured by a small clip. Thus disposed the film is pushed down flush with the top edge and secured, if need be, by other clips. After the developing the film can be readily lifted out and treated in other baths.
���The long'film is developed in the spirals of the holder
��A Perfect Five-Pointed Star Drawn with a Compass
WITH a compass draw a circle. Divide its peripher>- into 5 equal parts, stepping it off with a divider, and number the division points from i to 5. Draw a straight line from aivision point I to 3, from 2 to 4, 3 to 5, 4 to I and from 5 to 2. The result is a perfect star, the size of the star depending on the size of the circle.
��The Amount and Distribution of Water on a Farm
AFTER a pure water supply for the L farm is made available, the things to be considered are the quantity of water needed, choice of pumping equipment, and means of storage and distribution. The quantity required depends on the power used and whether the serv^ice is for the entire farm or for the house only. Hand- operated systems are applicable where small quantities are required for house service only; but in case water is wanted for stock, also, the use of a windmill, engine, electric motor or hydraulic ram is neces- sary. If a windmill is used the storage should be large enough for at least three days' supply, to provide water in case of calm weather Where the other sources of
��power are used the storage capacity need not exceed one day's supply. The following table gives approximate quantities of water required per day:
Each member of the family for
all purposes 25 to 40 gallons
Each cow will require 12
Each horse will require 10
Each hog will require 2^ '"
Each sheep will require 2
The water consumption will var>'^ from day to day and with the seasons. Fire protection should also be considered, and in determining the size of tank the maximum amount likely to be required should be provided.
For a family of 6 persons a 200-gal. sup- ply should be sufficient if the water is used for the house only. On a farm where water is supplied to a family of 6 persons, 10 horses, 12 cows, 25 hogs and 15 sheep, the daily storage supply should be at least 500 gal., exclusive of the amount provided for fire protection.
��Removing a Heavy Truck-W^heel Without a Chain-Block
THE body of a motor truck usually overhangs to such an extent that it is impossible to use the chain-blocks for re- moving a heavy wheel. The method illustrated has been used with excellent results, and it requires the ser\-ices of only one man. The wheel is jacked high enough to put a plate and rollers imder it. The plate should be about 18 in. square and ^ in. or more thick. The rollers are
���Plate with rollers beneath to make a movable platform for removing a heavy truck- wheel
made of i-in. pipe 18 in. long. The car is lowered until the wheels rest on the plate and it can be easily pulled out on the rollers. — Lester Jones.