MECHANICS AXD USEFUL AETS. 119 



The second patent embraces the dividing of the skate, and connecting the 

 two parts by a spring, and having the runner elastic, whereby the skate 

 yields, and the back part rises with the heel, when the weight of the body is 

 thrown upon the front part of the skate. 



ENLARGING AND REDUCING MAPS AND DESIGNS. 



James Murdock, of London, has taken out a patent for the purposes above- 

 named. The invention consists in transfering a map or a design to a sheet 

 of India-rubber hi an unstretched state ; then stretching the material equally 

 hi all directions, by having it secured in an expanding screw frame. This 

 process enlarges the map or design. To make a design or a map smaller, it 

 is transferred to the India-rubber sheet when it is in a stretched state, which is 

 afterwards allowed to contract equally on all sides. 



PROTEAN FOUNTAIN PEN. 



The above designation has been given to a pen patented by Mr. flf. A. 

 Prince, of Brooklyn, IST. Y. Protean is a word lately coined in Great Britain 

 to designate one of the forms of hardened caoutchouc, from which material, 

 under Goodyears patent, this pen, or rather pen-holder, is manufactured. 

 The handle is hollow throughout, and is filled with ink either by suction 

 through the mouth or by the aid of a small piston, after which the top is 

 tightly closed. The pen is attached hi the usual way, but the ink-tube or 

 handle is continued underneath and bent upward so as to shut its open end 

 against the under side of the pen near the point. "When pressed on the 

 paper a sufficient opening is made for air to enter. In this position ink con- 

 stantly escapes, while air enters at intervals and rises to the upper end of the 

 handle. A small spring of protean fixed within the tube continually presses 

 against the pen to serve as a conductor and prevent the possibility of the ink 

 being driven back, while provision is made by suitable cavities near the base 

 to catch any reflowing ink from the point, when the position of the pen is 

 accidentally reversed, and prevent it from soiling the fingers of the operator. 



IMPROVEMENTS IN LAMPS. 



An improved entry lamp has been recently patented by Chas. "W. Felt of 

 Salem, Mass., the object of which is to effect a saving hi light-producing 

 material gas, oil, or other burning fluid, used hi lamps placed in entries of 

 buildings (or situations where light is needed at short intervals), by reducing 

 the light to the minimum burning point when it is not needed. The con- 

 struction is as follows: the lamp is placed in a socket of a small metal plate, 

 which plate is secured by screws to any wooden fastenings in the entry. 

 The wick tube of the lamp has a small outer tube, which is capable of sliding 

 up and down on it. "When it is slid down, a greater portion of the wick will 

 be exposed to the ah 1 , consequently the lamp will give more light ; when it is 

 raised a very small portion of the wick is exposed, consequently the light is 



