MECHANICS AND USEFUL ARTS. 121 



safe, rnade of Franklinite, or spiegeleisen, combined with welded 

 steel and iron. It is cylindrical, and the top is raised to open the 

 safe or lowered to close it by a very strong vertical screw in the 

 centre of the cylinder. As the top is raised, the wood-work, con- 

 taining drawers and pigeon-holes, also is raised, so as to become 

 accessible. A combination lock fastens the top when closed, so 

 that it is held in a very secure manner. This safe appears to be a 

 very difficult thing for burglars to deal with, and we judge will 

 not often be attempted by that ingenious fraternity. A desk-safe, 

 also of new style, exhibited by the same firm, is worthy of notice. 



An application of electricity to bank locks, exhibited by the 

 Electro-Bank Lock Company, No. 9 Willoughby Street, Brook- 

 lyn, is a most ingenious affair. A combination lock is worked 

 entirely by electro-magnetism, and is placed within the safe on 

 the back wall, opposite the door. Its wheels are worked by elec- 

 tro-magnetism, the circuit being controlled entirely by circuit- 

 breakers placed in an office desk or any other convenient place. 

 No one can unlock the safe without knowing the combination, and 

 no key-hole or any other aperture in the walls of the safe exists 

 whereby powder can be inserted. Burglars could only enter a 

 safe provided with this lock by actually penetrating the wall. 

 The lock itself is absolutely exempt from all tampering. 



Among minor steam-engineering devices we noticed the Ameri- 

 can Eagle Steam Gauge, exhibited by the American Eagle Steam 

 Gauge Co., 190 Market Street, Newark, N. J., belonging to the 

 type known as mercurial gauges. It consists of a cast-iron cham- 

 ber fitted to receive a thin corrugated steel diaphragm or disk, 

 properly tempered, and plated with nickel, to prevent corrosion. 

 The pressure acts upon the under side of it, the mercury covering 

 the top side of the same, from which extends an open vertical 

 glass tube, supported and protected by a metal case, having a 

 graduated scale of pressure. Any slight movement of the disc 

 will fill the tube with the mercury to a greater or less degree, 

 whereby the pressure is correctly indicated. There is a screw by 

 which the starting-point of the mercury can be readily adjusted, 

 so that, whatever the temperature of the surrounding atmosphere 

 may be, the indication of the pressure will be correctly indicated. 



A recording pressure-gauge is shown by Charles G. Willing, of 

 88 John Street, New York, which gave a continuous and exact 

 record of the pressure, and the time at which the pressure was 

 sustained, automatically. The principle of recording is the trac- 

 ing on a rotating disk of a pencil point in the end of the index 

 hand. 



W. H. Place, 8 Attorney Street, New York, exhibited an im- 

 proved governor and valve, of novel construction, and apparently 

 of great effectiveness. Mr. Place, the inventor, was formerly 

 Chief Engineer of the Central American Transit Company. His 

 invention consists of a vertical cylinder or case, in which are 

 placed and attached thereto a series of inclined or spiral-formed 

 ribs, within which revolves (in water or other liquid) a propeller- 

 wheel, revolving and leading in an opposite direction from said 

 spiral ribs in said cylinder, making the shaft, by passing through 



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