I. “Old Home Receipt:” Glue 2 lbs., soaked over night, to New Orleans molasses 1 gallon. Not durable, but excellent while it lasts.
II. Glue 10½ lbs., molasses 2½ gal., Venice turpentine 2 oz., glycerine 12 oz.; mix as directed above.
CHAPTER XV.
THE HEKTOGRAPH.
For obtaining multiple copies of writing, the apparatus called the Hektograph or Papyrograph has been extensively adopted. In general terms it consists of a tray filled with a jelly like composition. Any imprint made upon the surface with aniline ink can be transferred to paper by simple pressure. The tray filled with composition is called the tablet. It is thus prepared.
The tray may be made of tin or even of pasteboard or paper, and should be about one half an inch deep. It may be of any size, according to the work it is to do. The composition is made from the best gelatine and glycerine. One ounce by weight of gelatine is soaked over night in cold water, and in the morning the water is poured off, leaving the swelled gelatine. Six and one-half fluid ounces of glycerine are now heated to about 200 F. (93 C.) on a water bath preferably, and the gelatine is added thereto. The heating is continued for several hours. This operates to expel the water and to give a clear glycerine solution of gelatine.
The composition is then poured into the tray, which must be perfectly level in order to obtain a surface nearly even with the edge. It is then covered so as to keep off the dust. The cover of course must not come in contact with the smooth surface. In six hours it will be ready for use.
The original copy that is to be reproduced is made upon ordinary paper in aniline ink. One formula for the ink reads as follows: Aniline violet or blue (2 R B or 3 B) 1 oz., hot water 7 fluid oz.; dissolve. After cooling add alcohol 1 fluid oz. and glycerine ¼ fluid oz., a few drops of ether and a drop of carbolic acid. Keep in a corked bottle. Other formulæ are given in chapter XVII.
The writing is executed with an ordinary steel pen. The lines should be rather heavy so as to show a greenish color by reflected light.
The surface of the pad is slightly moistened with a wet sponge and is allowed to become nearly dry. The paper is then laid upon it and smoothed down. This is best done by placing a second sheet over it and rubbing this with the hand. No air bubbles must remain between the copy and the tablet, and the paper must not be shifted.