Page:Popular Science Monthly Volume 90.djvu/162

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��Popular Science Monthly

��the material a difficult proposition. The shop cleaners deposit the metal in the box as it is gathered. To provide for easy- removal a door is placed on top of the box and also one in front, both being locked with a key. — ^J. R. M inter.

��White or light tinted paint required (i gal. covers about 350 sq. ft., 2 coats); divide 3,044 sq. ft. by 350 = 8| gal.

Darker colors (i gal. covers about 400 sq. ft., 2 coats); divide 3,044 sq. ft. by 400 = 7^ gal.

An average painter will brush on well about 150 sq. ft. of paint per hour, i coat. Divide 3,044 sq. ft. by 150 = 20.29 hours; call it 20^ hours for i coat, one man, and 40^ hours for 2 coats. Add 3 hours for mixing colors, setting and moving ladders, etc. Total 435 hours.

��Coloring Electric Globes for Decorative Lighting

TO color electric-light globes, make a coating as follows: Remove the gelatin from a quantity of discarded photographic films and dissolve them in equal parts of ether and alcohol; then color with aniline. This makes a coating that is impervious to water. Another method is to soak a small portion of gelatin in cold water until it has taken up all the water it can hold, pour off the surplus and add some boiling water — ^just enough to melt it — then strain it through several folds of cheesecloth. While still hot add a little aniline color, previ- ously mixed in a very little cold

water. Dip the globe in the warm, ,

solution and allow it to cool in a '^~^ -26'-—- — .^}Jlii^=^^^=^i^

vertical position to insure even Measurements for a house from which to obtain a base

coloring. This coating is not as ^°^ figuring cost of labor and materials for painting

good as the celluloid process first men- Material Cost:

tioned. — A. Ashmund Kelly. ioo lbs. white lead

bulk 2f gal., at $. . ..

Pure linseed oil .... 5 " "

Turpentine f " "

Japan drier I pt. "

���Estimating the Cost of Painting

��a Detached House

WHEN a house is to be painted the following plan will be found useful in determining the area to be painted and the cost of materials and labor:

Sides and ends 26-1-26-1-26+26 = 104 ft.

around the house. Height at corners, 16 ft., multiplied

by 104 1,664 sq. ft.

2 gables, 26 ft. wide multiplied by half

the height (6 ft.) 312

Dormer 2^X9 ft. = 22 sq. ft. 2 bay

window ends 3 X 8 ft. = 48 sq. ft. .. . 70 Side porch, rail and spindles (figure

solid)2|X4ft. = iosq. ft.; 2 sides. . 20 2 newel posts, 16 in. around; call it

1Ht.X5ft.high 15

Front porch floor, 8X23 ft. = 184 sq. ft.

Ceiling (figure solid) 8X23 ft. =

184 sq. ft 368

Front porch rails and spindles, (figure

solid) 2|X 16 ft 40

Front steps, risers and treads, 5 ft.

upX 5 ft. wide 25

4 porch columns, 4 ft. aroundX8 ft. high 128 Cornice facing and eaves overhang on

all sides 3Ht. X 1 15 ft. around =. . . 402

Total 3,044

��Color ,

��I lb.

��Amount of paint, 8^ gal. Total Cost..$.

Labor cost, 435 hours at cents per

hour

��Total I

Overhead expense, add % (15%?) of

material and labor cost

Profit, add % (20%?) of material and

labor cost

��Price to Charge Customer.

��Figure 3,044 sq. ft. at your regular price per sq. yd. or per square and see how your estimating method compares with the above.

��A Knitting Needle Used for Testing Milk

THE purity of milk is tested in Germany in a simple way. A polished knitting needle is held upright, dipped in the milk, and immediately withdrawn. If the milk is pure, some will adhere to the needle; but if water has been added, even in small

��proportions, the perfectly clean.

��needle will come out

�� �