** Cutting Lantern Slide Masks [245]

It has long been a puzzle to me why round cornered masks are almost invariably used for lantern slides, when most works of art are included within rectangular spaces, says a correspondent of Photo Era.  Certainly the present commercial masks are in very poor taste.  The worker who wishes to make the most of every slide will do well to cut his own masks, not only because of the fact just mentioned, but also because he can suit the size of the opening to the requirements of each slide.  Slides can be works of art just as much as prints; so that masking a slide becomes just as important as trimming a print, and equally worthy of individual treatment.  It is folly to give each slide a mask opening of uniform size and shape.

When many slides are to be masked, it becomes tedious work to treat each one separately, unless some special device is used.  The accompanying drawing shows a way to mark masks which is simple, practical and costs nothing.  The drawing is exactly lantern slide size.

Lay the slide over such a guide and note the size of the opening best suited to the picture.  This will be determined by the intersection of the ruled lines, which are numbered for convenience in working.  If the size wanted is No. 4 for width and No. 2 for height, place the guide over a piece of black mask paper and prick through the proper intersections with the point of a pin.  This outlines the desired

[Illustration:  Form for Marking Out Rectangular Lantern Slide Masks]

opening, which may then be cut out easily with a knife and straight edge.

The black paper from plate boxes and film rolls is excellent for making masks.  It should be cut up in pieces 3-1/4 by 4 in. and kept ready for use at any time.

** Relieving the Weight of a Talking Machine Reproducer [245]

Too loud reproduction from a record, the scratching noise sometimes heard and the forcing of the needle into a soft record, because the extension arm and reproducer are too heavy, can be remedied in the following manner:  Attach a small ring to the under side of the horn and use a rubber band to lift the extending arm slightly.  —­Contributed by W. A. Jaquythe, Richmond, Cal.

** How to Make a Thermometer Back in Etched Copper [246]

Etching copper is not a very difficult process.  Secure a sheet of No. 16 gauge copper of the width and length

[Illustration:  Copper Thermometer Holder]

wanted for the back of the thermometer.  In the design shown the extreme width is 3-1/2 in. and the extreme length 7 in.

Draw a design.  The one shown is merely suggestive.  The worker may change the outline or proportions as desired.  The decoration, too, may be changed.  The essential thing is to keep a space upon which to place the thermometer.  This design is in what is known as two-part symmetry.  A line is drawn down the paper and one-half of the outline and decoration worked out.  This done, the paper is folded along the center line, a piece of carbon paper is inserted between the folds and the design transferred on the inner surfaces by tracing with a pencil over the half of the outline previously drawn.  Trace the design and outline upon the metal, using the carbon paper.