924 



Popular Science Monthly 



wide by lO ins. 



the vertical rib of 540 pounds, which is 

 nearly the ultimate. It will not be 

 necessary to demonstrate further than 

 the figures given, that this kind of kite 

 flying is strenuous enough to hold a 

 man's attention when his whole battery 

 is aloft in a lo-pound wind. 



The reel is made of two- circles of 

 J^-in. material, 6 ins. in diameter. To 

 one side of these pieces, other circles of 

 ^-in. material, 12 ins. in diameter, are 

 glued cross-grain, and further secured 

 by a half-dozen clenched brads. To 

 the inner 6-in. circles nail slats of 

 ^-in. material, i in. 

 long. Cut the holes 

 in the center of the 

 ends I in. square; 

 put a square stick 

 tightly through 

 these holes, allow- 

 ing it to project 

 2}^ ins. at one end 

 and 3 ins. at the 

 other. Turn bear- 

 ings for the frame 

 in each of the pro- 

 jecting ends. These 

 will be I in. in 

 diameter. If you 

 have no lathe you 

 can whittle them 



with a knife and sandpaper. The frame 

 is made, as shown in Fig. 13. 



Obtain two grooved pulleys of the 

 diameter shown and a piece of sewing 

 machine belt. Put the belt on the 

 pulleys crossed. This will give it better 

 contact. Screw into the 12-in. pulley a 

 handle about i3^ ins. from the edge, and 

 you have a good stout reel which will 

 bring your string in four times as fast 

 as an ordinary reel. You will appreciate 

 this when you have tried both. No 

 checking arrangement is needed on 

 your reel. When necessary to check, 

 take the string in your hand and snub 

 around the projecting end of the axle. 

 Two iron pins, 15 ins. long, of ^i-in. 

 round iron, pushed slantwise toward the 

 front through the i-in. holes into the 

 ground, will take the strain. 



The construction and methods of 

 flying the Blue Hill box-kite and the 

 tetrahedral cell will be discussed in 

 the next issue of the Popular Science 

 Monthly. 



FIGURE 14 



How to Protect the Surface of a 

 Laboratory Table 



STRONG acids and other chemicals 

 of strong composition are continu- 

 ally spoiling the appearance of laboratory 

 tables. The following treatment may 

 therefore be found of service. It can be 

 recommended for preserving the ex- 

 perimenting table from the injurious 

 effects of strong acids or alkalis that may 

 be accidently spilled, provided the 

 liquids spilled are not left on too long. 

 Two solutions are required, as follows: 

 The first one consists of one part of 

 bluestone dissolved with one part of 

 chlorate of potash, 

 in eight parts of 

 boiling water. 



For the second 

 solution, dissolve 

 1 3^ parts aniline 

 h\'dro-chloride 

 (which a chemist 

 can obtain to or- 

 der), in 10 parts of 

 water. Having 

 thoroughly cleaned 

 the table, apply the 

 first solution as hot 

 as possible, and 

 with a flat brush. 

 Apply another coat 

 as soon as the first is dry, and then two 

 coats of the second solution. When 

 thoroughly dry, rub with raw linseed 

 oil, till polished, and wash with hot, 

 soapy water. A good black surface is 

 thus given to the wood, in addition to the 

 acid-resisting cjualities. After it is per- 

 fectly dry, a little linseed oil, applied 

 with a cloth, will also be of advantage. 

 A hard surface with considerable luster 

 is thus obtained, which will resist 

 damage to its surface, especially from 

 acids. — Wm. Warnecke, Jr. 



A Mission Stain 



ONE of the best and cheapest stains 

 for mission furniture can easily be 

 made by mixing black asphaltum with 

 turpentine. Any desired brown shade 

 can be obtained by varying the amount 

 of turpentine. Apply the mixture to the 

 work with a brush. After it has been 

 on a minute, rub it dry with a clean 

 cloth or cotton waste. It will dry 

 quickly and leave a dull mission finish. 



