A copy graph pad, or hectograph, as it is often called - from the Greek hekaton which means 100, and graph to write, hence to write a hundred - is a gelatine pad for duplicating a letter or a drawing.

To use a copygraph pad you must write your original letter with an aniline ink; then you lay it on the pad and rub it down with your fingers. When you remove the sheet an impression will be left on the face of the pad and if now you lay a sheet of clean paper on the pad, rub it and pull it off you will have a copy almost as bright and clear as the original. In this way as many as 50 or 100 copies of the original letter can be made.

To make a copygraph pad put 1 ounce of the best gelatine in enough water to cover it and let it stand for 24 hours. Put a tablespoonful of table salt into a cup of water, pour it into the outside can of a water jacketed pot. Put 6 ounces of glycerine in the inside pot, set the pot on the stove and heat it good and hot, or to be exact, to about 200 degrees Fahrenheit.

73 You can buy a good rubber stamp pad for a quarter. Rubber stamps, pads, and ink can be bought of the Everson and Reed Co., 88 Chambers St., N. Y. C.

Drain off all the water from the gelatine and put the latter in the glycerine while it is yet on the fire; stir the mixture slowly every once in a while in order to prevent bubbles from forming, and skim off the froth that forms on top of it. When you have a nice smooth mixture stir in a teaspoonful of oil of cloves to keep it sweet.

Next make a pan of sheet zinc a little larger than the letter you want to copy and 1/2 an inch high, or you can use a tin pie pan if you merely want to try it out. Set the pan on a level table, fill it with the hot mixture, let it stand over night and it is ready to use.