Le Prince allowed powdered resin to settle evenly on a copper plate, fixed the minute grains by heat, and then treated the plate with acid as if it were an etching. When the plate was cleaned the acid is found to have bitten a little line round each grain of resin, so that an aquatint made by this method consists of a series of small rings more or less thick. The different thicknesses are produced by stopping out some portions and re-biting others. The general effect of aquatint is delicate and pleasing, and it can be strengthened where necessary with a little etching. Aquatint helps its followers considerably, and a good aquatint made from a drawing or painting will often have luminous effects that are wanting in the original. There is one other method of aquatinting that must be mentioned, but there are more which are too numerous and too unimportant to require explanation here. It is a modern invention, and consists of coating the plate with resin dissolved in alcohol; when this dries it breaks up into little pieces, and the acid can penetrate between these pieces as in Le Prince’s method. But the resulting prints do not show Le Prince’s little circles, but small irregular polygons. Le Prince sold his secret to Charles Greville, and he passed it on to Paul Sandby, who not only became an eminent aquatinter but published a book in 1775 called _Twelve Views in Aquatinta_. This drew much attention to the beautiful new art, and it rapidly became very popular in England. English aquatinters, like English wood and stipple engravers, always liked colour, whether added by hand or printed in ink, and so we find that the large majority of English aquatinters enjoy the added beauty of colour. The publishers Ackermann and Boydell both deserve much honour for their consistent patronage of aquatints, and no doubt our splendid record in that art is largely due to their enterprise. Towards the latter part of the eighteenth century we already find several fine books with hand-coloured aquatint illustrations published in England, among these are W. Hodge’s _Select Views in India_, 1786; T. Hassell’s _Picturesque Guide to Bath_, 1793; Combes’ _History of the River Thames_, with aquatints by J. C. Stadler; E. Orme’s _Twelve Views of Places in the Kingdom of Mysore_, with aquatints by J. W. Edy; and H. Repton’s amusing _Sketches of Landscape Gardening_, with moveable plates to show how good his suggested improvements were, all published in 1794, and from this time for the next thirty years were numbers of books issued with coloured aquatints concerning domestic architecture. Early in the nineteenth century there are still numbers of books with aquatint views in them: J. Webber’s _Views in the South Seas_, published in 1808, and Boydell’s _Picturesque Scenery of Norway_, with aquatints by J. W. Edy, in 1820, and several more.