Page:Popular Science Monthly Volume 91.djvu/478

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462

��Popular Science Monthly

��A Tie for a Shoe Lace That Will Stay Tied

IT is not always the large things that annoy us most as a persistent vexation. By this is meant that when some important thing annoys us, we immediately set about correcting the trouble, but a small thing — too trifling to bother with — will worry us repeatedly and we give it no at- tention. A very good example of this petty an- noyance is shoe laces. Many times a day do we see people stop by the way- side and tie their shoe laces. Es- pecially is this true with new laces. One extra turn of the lace about the first loop made will produce a secure fastening even if not" drawn absolutely tight. The ordinary bow-knot used to fasten shoe laces is shown in Fig. i. The string A is given one turn about the string B at C, before the loop of string A is passed through. By making two wraps as shown in Fig. 2, at D, before passing the loop in string A through, a fastening is made that will not slip or shake loose. It is so simple that it is strange that you have never found it out before, but it does the trick and holds tightly. — Geo. S. Brown.

���Two turns in shoe lace tie will hold it tightly

��Keeping the Strands of a Rope End from Unraveling

THE three strands of the rope are separated as shown at A, then the strand marked I is turned over between 2 and 3, then 2 is turned over on 1 and between the base of 1 and 3, as in B. The end of the strand 3 is then run through the loop of 1 as in C and drawn up tightly as in D. The strands are then cut off close to the knot. — Tudor Jenks.

���The strand ends are tied into a knot

��Saving Chemicals by Machine Development of Film

THE amateur who undertakes to de- velop his own moving picture films finds many difficulties, which, to say the least, are discouraging. The films are long and unwieldy unless wound on drums or racks, nor can they be handled after being wet. If the drum system is used the space required for operation is prohibitively large for most amateurs. If the tank process is used there must be at least three tanks, one each for the developing, fixing and washing

��BELT PULLEY. 7l

���The upright and its attachments for driving moving picture film through the chemicals

solutions; and the space necessary for their installations, as well as the cost of the tanks themselves, puts it beyond the reach of the amateur at home.

In addition to the space required for the tank system, about 35 gal. of developer will be necessary to fill a tank that will handle 200 ft. of film. At the present price of chemicals this would cost about $20, and as it deteriorates rapidly whether it is used or not the development is rather expensive for a single film.

The experimental engineer for a moving picture concern in the west was forced by the limited size of his laboratory to install a developing, fixing, washing and drying apparatus for moving picture films, which

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