Popular Science Monihlu 



form and by examining the drawing it can 

 be seen that .1 and B are part of cones of 

 the same size. C is a plain cylinder, the 

 development of which has been ex- 

 plained earlier in this series. 



To develop the pattern for A: First, 

 draw the complete cone with apex at D 

 and base line at 1-9. Second, draw the 

 one-half bottom view, divide it into eight 

 equal parts, from these points project lines 

 up to the base line and then to the apex, 

 D. Third, with 1-D as a radius, strike 

 the arc E-F, get the correct length by 

 setting off sixteen spaces from the bottom 

 view as previously explained and draw 

 radial lines to apex D. Fourth, from 

 where the curved part of the scoop crosses 

 the radial lines going up from the base 

 line to the apex, draw lines over to line 

 \-D to get the true lengths as explained 

 in the last issue. Swing these lines over 

 on to the pattern until they cross the 

 same numbered lines coming up from the 

 arc E-F. Sixth, it will be noticed that 

 the curve of the scoop in A does not cross 

 the base line at the same place as one of 

 the radial lines, so we must use an "aux- 

 iliary" line such as we have used in a 

 previous problem. This is used in the 

 following manner: From the point where 

 the scoop curve crosses the base line, draw 

 a line to the bottom view and mark it X 

 as shown in the drawing. It can be seen 

 that it lies between 4 and 3. Measure 

 the distance from 4 to X and lay it off on 

 the pattern arc E-F as shown. This will 

 indicate the corner of the pattern. Do 

 the same for the opposite side of the pat- 

 tern, and the pattern for A will be com- 

 plete. 



Exactly the same method is used in de- 

 veloping the pattern for B. The steps 

 are briefly indicated as follows: First, 

 draw full cone. Second, draw one-half 

 bottom view and run lines to apex K. 

 Third, strike arc L-M with K-1 as radius. 

 Fourth, draw lines from points where 

 scoop curve crosses radial lines to line 

 K-\, to get true lengths. Fifth, swing 

 these lines in arcs to pattern. Make 

 crosses where they intersect same num- 

 bered lines. Sixth, make use of auxiliary 

 line X in exactly the same way as for 

 pattern A. Connect the crosses with a 

 curve and the pattern is complete. Make 

 allowance for seams and wiring as pre- 

 viously explained. 



01.5 



Cutting Asphalt After Removing 



Metal Covering 



ASPHALT is usually shipped in tin 

 i\ barrels. The metal is stripped olf 

 and the asphalt rolled up to the stopping 

 board; the wire shown, attached to the 





-Jk. 



Wm^^ 



Cutting asphalt taken from barrel with a 

 wire drawn through it with a windlass 



winding drum, is passed over and around 

 the asphalt to a piece of pipe under and 

 ahead of the stop board. When the drum 

 is turned it tightens up on the wire and 

 causes it to cut through the asphalt. 

 Kerosene is poured on the wire to make 

 it pass through the asphalt easily. 



Asphalt with covei> 

 mg stripped off- 



Cutting wire 



A- Loose end ot Aire 

 fastened to pipe 



H 



' Diagram of the table, stop, and v/indlass 

 for pulling the wire through the asphalt 



The barrel shape is first cut in half, 

 then each half is cut into quarters which 

 a man can handle easily. In warm 

 weather asphalt is soft, therefore it can- 

 not be cut or broken with an ax or other 

 tool, so this machine is a time and labor 

 saver. — George C. Peck. 



Intensifying Under-Exposed Blue- 

 Prints with Hydrogen Peroxide 



AN under-exposed blue-print can be 

 . intensified by moistening its surface 

 with a sponge dampened with peroxide of 

 hydrogen. Old blue-print paper which 

 would otherwise produce an indistinct 

 copy need not be thrown away if treated 

 with peroxide after the print has been 

 exposed and "fixed." 



