In using whitewash much difficulty is experienced in making it stick to the substance covered. A good way to prevent the coating from cracking and peeling off is to add 2 oz. of pure sodium chloride to every 1 gal. of whitewash mixture. This is not expensive, but should be secured at a drug store because some salts of sodium are not pure and will darken the whitewash. The sodium chloride should be added after the whitewash solution is made up. When this mixture is used in buildings it will destroy all vermin which it touches.
A Mechanical Camera
The young person who likes to draw will find the device illustrated of great assistance for outlining a portrait or a bit of scenery which can be filled in to make the picture. The camera consists of a box without a cover, about 12 in. long, 6 in. wide and 4 in. deep. An oblong hole is cut in one end, a small hole bored in the other, and a piece cut out of the lower edge so that one eye can be placed close to the hole. The oblong hole, shown by the dotted lines, is covered with a fine perforated cardboard, the kind used for working in mottoes with yarn. Supports are nailed in the corners of the box, their length being calculated to allow the operator to sit or stand, as desired.
Outlining a Portrait on the Perforated Paper Placed over the Oblong Hole in the Camera
The camera is used in the manner illustrated. If a portrait is to be drawn, then the one sitting for it must be quiet until the outlines are completed. The operator, looking through the hole, traces the lines on the cardboard between the perforations. When the outlines are drawn in this manner, the cardboard is removed and placed on the paper or cardboard used for the picture. The outline is then transferred by marking with a sharp-pointed pencil through the perforations on the outlines as drawn. After separating the two pieces, the markings can be connected with a continuous line and an exact outline will be obtained which can be filled in as desired. The outline picture is a sample of work done with the camera.—Contributed by Florence Thomas, Gordon, Ont.
Gauge Attachment for a Pocket Rule
The base of the gauge A is cut from a block of hard wood, about 2-1/2 in. long, 1 in. wide and 3/8 in. thick. A notch is cut in one side to admit the rule and the wedge B, which has a slot that slides on a pin in the base. A small metal clip keeps the wedge in place. The gauge can be readily set on the rule at any mark.