622 



Clip for Carrying Pipe in the Vest 

 Pocket Safely 



A GREAT number of pipe users adhere 

 to the straight stem for reasons 

 known to the habitual smoker. However, 

 carrying such a pipe is somewhat difficult. 



Popular Science Monthly 



A clip similar to the one used on a fountain 

 pen for holding pipe in the vest pocket 



If carried in the hip pocket it is liable to be 

 broken, and if in the vest pockets it is liable 

 to be dropped out and lost. For the worker 

 who likes to and can have a frequent draw, 

 it is most readily carried in one of the upper 

 vest pockets. The illustration shows an 

 easily made aluminum or brass clip that is 

 bent to fit the stem of the pipe and which 

 will securely fasten the pipe to the edge of 

 the pocket. The idea was conceived after 

 the writer had lost a few broken-in good 

 ones, himself. — F. W. Bentley. 



A Silvering Process for Glass Instru- 

 ments and Mirrors 



DISSOLVE 2.5 grams of silver nitrate 

 in 100 c.c. of distilled water, and add 

 ammonia until the precipitate just goes 

 into solution. Make up the solution to 

 250 c.c. When this has been done, prepare 

 another solution containing .5 gram of 

 Rochelle salt in 250 c.c. of water; boil the 

 solution to dissolve the salt more rapidly. 

 Keep both solutions in tightly stoppered 

 bottles in the dark when not in use. 



The surface to be silvered must be 

 thoroughly cleaned by washing first with 



a strong alkali solution, then with dilute 

 nitric acid, and finally with distilled water. 

 After each washing, the surface should be 

 rubbed with moist cheesecloth. A solu- 

 tion of stannous chloride in water to which 

 a few drops of hydrochloric acid have been 

 added is then poured gently and evenly 

 over the surface, which should then be 

 well washed in tap water. Care should be 

 taken not to touch the prepared surface 

 with the fingers after the treatment 

 with tin chloride. 



While still wet the object is placed in a 

 waxed dish or waxed paper, and a mixture 

 of equal volumes of the two solutions 

 already prepared quickly poured over it, 

 avoiding splashing and air-bubbles. In 

 about an hour the silvering will be com- 

 plete; the liquid may be poured off, and 

 the article dried. The silvered surface 

 should never be touched by the fingers. 



The best shellac for such a surface is 

 prepared by dissolving 5 parts by weight 

 of gutta-percha; 20 parts by weight of gum 

 damar in 75 parts by weight of benzene. 

 If these articles are not readily obtainable, 

 the surface may be varnished with a very 

 dilute shellac varnish. By this process 

 anyone can easily construct hygrometers, 

 mirrors, reflectors, and many other kinds 

 of useful apparatus. 



Holding the T-Square on the 

 Drawing- Board 



WHEN using a small drawing-board 

 not supported by a stand or other 

 regular holding arrangement, the most 

 convenient position in which to hold it 

 while seated is to tilt it against the edge 

 of the table. 

 As a result, the 

 T-square must 

 be dropped to 

 the base after 

 each time it is 

 used. The il- 

 lustration 

 shows how a 

 simple attach- 

 ment for the board and square can be 

 made and applied which will hold the square 

 at all times in place on the face of the 

 board. A number of very small screweyes, 

 two light rubber bands, and a piece of light 

 but strong cord are all the materials 

 needed. It is easily pushed up and down 

 as required, and does not interfere with the 

 placing or withdrawal of work. 



A cord on T-square 

 head to hold it on board 



