Fig. 874.—Reading wheel desk.
At the beginning of the seventeenth century there was at Lyons a very remarkable mansion built by a man named Nicholas Grollier de Servière. This house was filled with all the most remarkable curiosities and inventions of the period. The owner belonged to an ancient family. His great-uncle, Jean Grollier, had amassed a magnificent library, the best in France. His father was also a celebrated adherent of Henry IV., and M. Servière himself had inherited much scientific taste and intelligence from his ancestors. His house was full of curiosities, ingenious machines, and mysterious clocks, concerning some of which things we shall have something to say in this chapter.
M. de Servière’s ingenuity was first apparent in the circular reading desk, or wheel-desk, on which he put all the books he was likely to require within a certain time. He seated himself by this revolving desk, and then was enabled to read any book or paper he desired by merely turning the wheel with his hands and thus bringing it under his vision. In these days it is equally possible to collect useful articles either of an electric nature or otherwise. We have already described the electric pen and the writing machine, with some other things which might be included in our list of domestic appliances, but the Chromograph has not been yet illustrated.
Fig. 875.—The chromograph.
The Chromograph.
When we have written with a certain well-known violet “ink” upon a sheet of paper and applied it to a soft gelatinous surface and rubbed it a few times, we shall obtain an impression of the writing on the gelatine. By pressing blank sheets of paper upon this we may pull off quite a number of copies of our letter or circular. This practice is now so well known that it is scarcely necessary to detail it. The layer of gelatine is made up as follows, and any of the recipes will suffice.
1. Gelatine 100 grammes, water 375 grammes, glycerine 375 grammes, kaolin 50 grammes. (Lebaigueé.)
2. Gelatine 100 grammes, dextrine 100 grammes, glycerine 1000 grammes, sulphate of baryta q.s. (W. Wartha.)
3. Gelatine 100 grammes, glycerine 1,200 grammes, bouillie de sulphate de baryta, strained, 500 cubic centimètres. (W. Wartha.)