The other consists of a hinged portion that will enter the snow on a back thrust. As the ski end is thin, a block of wood must be attached to it on the upper side, and the projecting piece hinged to the block. The bevel at the end allows it to dig into the snow when the ski starts back. In going forward, it will swing out of the way freely.
Crystallization Shown on a Screen
The formation of chemical crystals can be shown in an interesting manner as follows: Spread a saturated solution of salt on a glass slide, or projection-lantern glass, and allow it to evaporate in the lantern's light or beneath a magnifying glass. The best substances to use are solutions of alum or sodium, alum being preferable. Ordinary table salt gives brilliant crystals which reflect the light to a marked degree. For regular formation, where the shape of the crystal is being studied, use a solution of hyposulphite of soda.
Many startling facts may be learned from the study of crystals in this manner, and watching them "grow" is great sport even to the chemist.—Contributed by L. T. Ward, Des Moines, Iowa.
Furniture Polish for Fine Woods
Boiled olive oil, to which a few drops of vinegar has been added, makes an excellent furniture polish for very fine woods. It will be found to work nicely on highly polished surfaces, and also for automobile bodies. It is applied in moderate quantities, and rubbed to a luster with a flannel cloth.
Enlarging Photographs
By A. E. Swoyer
When the photographer wishes to make an enlarged print from a small negative, he arranges a suitable light and condensers back of the negative and by means of a lens projects the resultant image upon a sheet of sensitive paper. Owing to the comparative weakness of the light, however, it is necessary either to use bromide paper or some of the faster brands of developing-out paper. If a more artistic medium is desired, a glass positive must first be made and enlarged to produce a negative from which the final prints will be made by contact. This process is somewhat clumsy and expensive, for if any retouching or doctoring is to be done, it must be upon a glass surface, either that of the two negatives or of the intermediate positive. As all of this work is done by transmitted light, there is the loss of fine detail common to all enlargements.