146 



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 



