As a series of impressions, illustrative of the method pursued in the production of a Chromo picture, would much more clearly explain the process than any mere description, such a series is here presented.

An ordinary tinted Lithograph, for which three or four printings only would be required, might have sufficed for this purpose, but, in order to encourage the obviously growing taste of the day, something more elaborate has been produced - a fac-simile of a water-colour drawing. A young Liverpool Artist, of great promise, Mr. H. B. Roberts, whose works find ready purchasers, has prepared a drawing which it is hoped will be acceptable to those who take an interest in such matters; to whom it may be satisfactory to know that the artist has kindly put upon the stone so much of the picture as was necessary to furnish a key for the whole; that is, the stone to impressions from which all the impressions from the other stones must be adjusted. But though it is indispensable that this key-stone shall be first prepared, it does not follow that it must be first printed from it is usually the last.

66

The following extract from a Memoir of Lithography, quoted in the preface to one of the works published by the brothers Nicholson, the date of which is 1821, will explain the process, so far as a single printing is concerned; and it is only necessary to state that the more elaborate works are produced by repeating the same process for each of the colours introduced : Lithography is founded on mutual and chemical affinities, which hitherto have never been applied to the art of Engraving. The dislike which water has for all fat bodies, and the affinity which compact calcareous stones have for both water and greasy substances, are the basis on which rests this new and highly-interesting discovery. The art of Lithography may be divided into two parts; the first consists in the execution of the Drawing, on a stone which has been made perfectly smooth and level, with an ink composed of greasy materials, in the same way as one would execute a drawing on paper with common ink. The second consists in obtaining impressions from the stone. To obtain these impressions, the printer wets the whole surface of the stone; but as the greasy ink which constitutes the drawing has a natural aversion for water, those parts of the stone alone which are not covered with the ink imbibe it. The printer, while the stone is still wet, passes a thick and greasy ink over its whole surface; and the lines of the drawing receive the ink, while the wet surface of the stone refuses to take it. A sheet of paper is now strongly pressed on the stone, which, receiving the printing ink that has been applied to the drawing, gives a reversed fac-simile of the original one. The stone is wetted afresh, and afresh charged with ink, and thus a series of impressions are obtained.”

It may be stated that the plan here described is, with but little variation in some minor respects, that which is followed at the present day.