Popular Science Monthly 



459 



A Convenient 



A STURDY shoe 

 rack can be 

 constructed as fol- 

 lows ; Fasten a 

 board along tlie 

 wall , or if preferred, 

 on tlic door of the 

 bedroom closet, 

 and then attach a 

 metal strip as 

 shown. The metal 

 support may be of 

 tin or sheet-iron, 

 but if made of brass 

 and nickeled it will 

 have a rriuch better 

 appearance. The 

 shoes are hung 

 by the heels . — 

 Geo. W. Greene. 



An Exceedingly Sim- 

 ple Arrangement for 

 Keeping Your Shoes 

 Out of the Way 



Shoe-Rack 



How to Calculate Distances 



IT is often necessary to measure ap- 

 proximate distances from one object 

 to another quickly, as in photographing 

 with a Kodak. An instrument that 

 enables one to make such measurements 

 can readily be made, using the angle of 

 incidence as the principle upon which to 

 work. Such a device, made according to 

 the description, is simple and compact. 

 It can be constructed either of hard- 

 wood, or sheet metal, cut to 

 the size and shape shown in 

 the illustration. Running 

 along the top of the device is a 

 sight tube, consisting of a 

 small metal tube soldered or 

 securely fastened with wire. 

 A le\'el, in the form of a metal 

 hand, is fastened as shown, 

 the hand being left free to 

 swing back and forth along 

 the face of the instrument. 



The device is now complete, 

 except for the markings, which arc deter- 

 mined as follows: Selecting a lc\-el 

 ground, a distance of loo feet is measured 

 off. Standing at one end of the measured 

 distance, sight through the tube to the 



The Angle of In 



cidence Is the Foun 



dation Principle 



base of an object placed at the other end 

 of the measured distance. By base is 

 meant the base line, or point of meeting 

 between the ground and object. After 

 carefully sighting in this manner, at the 

 same time allowing the hand to swing 

 free, the hand is 

 now caught under 

 a finger and pressed 

 against the face of 

 the instrument, to 

 prevent further 

 move m e n t. A 

 mark is now made 

 at the point of the 

 hand, and this in- 

 dicates loo feet in 

 future measure- 

 ments. 



The other dis- 

 tances are measur- 

 ed in the same 

 manner, care being 

 taken always to be 

 on a level ground; 

 the measuring of 

 the short distances 

 can be done in- 

 doors very conveniently. Obviously, the 

 nearer an object is to the observer, the 

 more the instrument must be tilted to 

 sight at the base line of an object, and 

 vice versa. Therefore, to make accurate 

 measurements of distances, the instru- 

 ment must always be used by a person 

 standing up straight, and one of the same 

 height as the one who made the mark- 

 ings, for they would not be absolutely 

 correct for anyone of different height. If 

 extreme compactness is not a 

 requirement, the instrument 

 can be fastened to a rod, with 

 a pivot, and this pressed into 

 the earth to form a support, 

 thus allowing it to be used by 

 anyone. The object sighted 

 at should always be on a le\'el 

 with the observer, in order 

 that the proper distance be- 

 tween the two may be found. 

 Such a device is especially 

 valuable to the amateur 

 photographer in determining the dis- 

 tance between his camera and the 

 object to be photographed, and will 

 greatly reduce the number of failures 

 due to incorrect judging of distances. 



