For illustrations it is often an advantage to show an object with a perfectly plain background and no deep shadows.  When using the stand as illustrated this is a very simple matter.  Figure 1 shows the side, and Fig. 2 the front view of this stand.  The stand is very easily constructed from pipe and pipe fittings.  The main pipe of the stand will need to be of proper length to suit the focus of your camera.  This can be determined by finding the length from the lens to the object after the bellows are extended to their full length.  The arms holding the glass, as shown in the sketch, should be set at a point about the middle of the main tube.  The cross that holds the middle arms should be 3/4 in. one way and 1/2 in. the other.  This will allow for adjustment of the glass table.  A small set screw provided in the back of this cross will hold the table in any position desired.  The pipes and other connections are all 1/2-in. and the lengths of the pipes are made suitable for the size of the camera.  When a small object is to be photographed it is placed upon the glass table and the background fastened to the board.  In this manner small objects can be photographed without any deep shadow on one side.  The bottom cross and ells should be corked so as to prevent any slipping and damage to the floor.

** Home-Made Pocket Lamp [149]

A simple and safe pocket lamp that will last for about 6 months without extra expense can be made at home for a few cents.

Have your druggist take a strong vial of clear glass, or a pill bottle with screw or cork top and put into it a piece of phosphorus about the size of a pea and fill the bottle one-third full of pure olive oil that has been heated for 15 minutes—­but not boiled.  Cork tightly and the result will be a luminous light in the upper portion of the bottle.  If the light becomes dim, uncork and recork again.  The lamp will retain its brilliancy for about 6 months.  This makes a perfectly safe lamp to carry.  These lamps are used by watchmen of powder magazines.  Care should be exercised in handling the phosphorus, as it is very poisonous.

** How to Make a Tangent Galvanometer [150]

Secure a piece of wood 1/2 in. thick and cut out a ring with an outside diameter of 10-1/2 in. and an inside diameter of 9 in. and glue to each side two other rings 1/4 in. thick with the same inside diameter as the first ring and 11 in. outside diameter, thus forming a 1/4-in. channel in the circumference of the ring.  If a lathe is at hand this ring can be made from a solid piece and the channel turned out.  Cut another circular piece 11 in. in diameter for a base.  Make a hole in the center of this piece 1 in. wide and 6-5/16 in. long, into which the ring first made should fit so that its inner surface is just even with the upper surface of the baseboard.  The ring is held upright in the hole by a small strip screwed to the base as shown.  All screws and brads that are used must be of brass.  The cutting of these circular pieces is not so difficult if a band saw driven by power is used.  They can be cut by means of a key-hole saw if a band saw is not accessible.