latter may be strained on a drawing or any other smooth board, by damping the sheet, and after pasting the edges, stretching it down while damp. Silk, linen, or other stuffs require to be carefully stretched on a knitting or other suitable frame. Take great care to allow, whatever you use, time to dry before applying the liqueur diaphane. All kinds of screens, lamp-shades, and glasses, lanterns, &c., &c., may be made in this way, as heat will produce no effect upon them. The transparent pictures are successful, because they may be hung on a window frame or removed at will, and the window blinds are far superior to any thing of that kind that have yet been seen. Instead of steeping the designs in the transparent liquor at the time of printing them, which was previously done in order to show their transparency to the purchaser, but which was practically objectionable, as the paper in that state was brittle, and devoid of pliancy, necessitating also the use of a peculiarly difficult vehicle to manage (varnish) in applying it to the glass, the manufacturer now prepares his paper differently, in order to allow the use of parchment size in sticking them on the glass. The liqueur diaphane, which is finally applied, renders them perfectly transparent. In this mode of operation, no delay is requisite, the designs being applied to the glass immediately after laying on the size, taking care to press out all the air bubbles, for which purpose a roller will be found indispensable. The designs should be damped before the size is applied to them. We are of opinion that this art may be applied to the production of magic-lantern slides, dissolving views, and dioramic effects; though we are not aware whether such experiments have been tried. 551. WATER-COLOURS USED IN DRAWING Indian Ink.--The best is stamped with Chinese characters, breaks with a glossy fracture, and feels smooth when rubbed on the plate. Hair Pencils are made of camel's-hair; if they come to a point, when moistened, without splitting, they are good. Drawing Paper.--That made without any wire marks, and called wove paper, is the best; it is made of various sizes and thicknesses. To make a good white.--Clarify white lead with white-wine vinegar. After the powder has settled, pour off the vinegar, put the powder into a glass of water, stir it, and pour the water off while it is white into another glass; when it is settled, pour off the water, and an excellent white will be obtained. To this add gum enough to give it a gloss. 552. DIRECTIONS FOR MIXED COLOURS Ash Colour.--Ceruse white, Keating's black and white, shaded with cherry-stone black. Bay.--Lake and flake white, shaded with carmine; bistre and vermilion shaded with black. Changeable Silk.--Red lead and masticot water, shaded with sap-green and verdigris. Another.--Lake and yellow, shaded with lake and Prussian blue. Cloud Colour.--Light masticot, or lake and white, shaded with blue verditer.