202 NEGRETTI AND ZAMBEA, HOLBOEN VIADUCT, E.C., 



592 Duckham's Patent Suspended and Self - Acting 

 Weighing Machines and Dynamometers, adapted to the 

 Standards of all nations. 



They are entirely self-acting, and indicate the weight of 

 even the most ponderous goods, during the ordinary operation 

 | of loading or unloading. 



They combine extreme simplicity and unlimited power 

 I with general utility, accuracy, low price, and economy in 

 I working. 



They are invaluable to MERCHANTS, SHIPPERS, DOCK 

 AND RAILWAY COMPANIES, as a ready and costless means of 

 ascertaining the weight of merchandise in transit ; to IRON- 

 MASTERS, that they may ascertain the weight of material even 

 Fm. 592. during the process of manufacture ; to CHAIN, WIRE, AND 



ROPE MANUFACTURERS AND PURCHASERS, thab the strength as well as the weight 

 of such material may be proved ; to SHIP OWNERS, that the weight of cargo and 

 stores may be checked by the simple operation of lifting the same on board ; to 

 ENGINEERS, BOILER-MAKERS, HARD-WOOD MERCHANTS ; and in fact, to ALL and 

 any who deal with goods by weight, or are interested in knowing the strength, of 

 materials or machinery, that the goods may be weighed, and strains and strengths 

 tested, by a process which is entirely free of expense. 



" The inventor provides an open-top cylinder, which is filled with water or oil, 

 and fitted with a piston and pressure gauge. For the purpose of weighing goods 

 the cylinder is slung from an ordinary crane hook. The goods are attached to the 

 piston rod, and immediately these are lifted as in process of loading or unloading 

 ships or wagons the weight is denoted on the dial. Nothing can be more simple." 

 Mechanic's Magazine. 



PRESENT PRICES FOR PATENT SUSPENDED WEIGHING MACHINE. 



B. a. 



12 cwt. to 3 tons capacity, 45 Ibs. weight 17 17 



5 tons ditto 56 24 



10 tons ditto 85 30 9 



30 tons ditto 280 . . . . . 50 



593 Hearson's Strophe-meter, or Revolution Indicator. This Instrument indi- 

 cates, by means of a pointer on a marked dial, the number of revolutions per minute 

 an Engine is, at the time, revolving. 



It is so designed that when Engines are subject to incessant momentary 

 fluctations of speed, the needle points steadily at a number expressing the mean 

 velocity. 



It will be found particularly useful for Locomotives (the dial being graduated 

 in miles per hour), for Spinning Machinery, and for Ships. 



The Instrument is worked by means of a rope passing round a pulley on the 

 shaft of the Engine, or in connection with a friction roller against a coupling of 

 the shaft. 



For description of the Instrument see paper read at the Institute of Naval 

 Architects, and published in the Transactions for 1874, and also article in No. 4 

 Annual of Royal School of Naval Architecture. 



PRESENT PRICES. 



s. d. 



Strophometer with 9-inch Dial 10 10 



Leading Pulleys for ditto 036 



Connecting Arrangements for ditto .... from 2 10 



