242 ADDENDA. 



HYDEOSTATIC WEIGHING MACHINES, for any weight from 1 ton up to 100 

 tons, or for showing the force exerted in ploughing, etc. The action of these 

 machines is to weigh goods by suspension as in the ordinary circular balance, 

 so that the mere act of lifting them by crane for shipment, etc., shows the 

 weight at the same time. Attached at the end of the chain or pulley with 

 which the objects as hogsheads, cannon, timber, plate armour for ships, etc., 

 are slung or lifted, their value can hardly be over-estimated. 



SIZES, PEICES, AND WEIGHTS OF THE MACHINES. 



2908. Three ton machine, of about 501bs. weight . . . 14 10 



2909. Five 60 . . . 18 10 



2910. Ten 90 . . . 20 



2912. Twenty ton 180 ... 28 10 



2913. Thirty 250 . . . 36 



2914. Fifty 330 . . . 50 a 

 The system admits of no limit in power, and machines may be made to order up to any 



capacity. Those of 10, 20, 30, 40, and 50 cwt. capacity, same price as three ton machines. 



2915. MAP METEE (Improved), with scale divided to 176, each division being equal to 



5 yards, to correspond with the Ordnance Survey of 6 inches to the mile 



14 6 



2916. Sounding and Dredging Apparatus, as used by the Admiralty for measuring 



great depths in the sea, or bringing specimens from the bottom. Price 

 according to size and depth for which it is required 2 2 to 10 10 



2917. TELESCOPES for tourists, in aluminium, very light, viz., about one-third the 



weight of the usual kinds, with caps and straps, as ^5,^354, 1374, and 1375, 



4 draw with li-inch. object glass, 4 4 I 4 draw with ! T V m - object glass 6 6 



l T 4 -inch. 5 15 I 2-inch. 7 16 



2918. TELESCOPES, marine, in aluminium, of light weight, as above : 



1 draw, with ly^-in. object glass 580 

 ' 



l T Vin. ' 600 



1 draw, with 2-in. object glass 7 15 

 2-i-in. 8 12 6 



