52 EEPOET OF COMMISSIONER OF FISH AND FISHEEIES. f50] 



Diameter of the cross-head pins inches.. 2 



Length of the cross-head pin journals ' do 2 



Ordinary speed of the engine, in revolutions, per minute 300 



Eate of heaving in the starboard anchor, in fathoms, per minute 4 



Eate of heaving in the port anchor, in fathoms, per minute 3-^ 



Length of the starboard chain fathoms.. 120 



Length of the j)ort chain do 120 



Weight of the starboard chain pounds. . 14, 745 



Weight of the port chain do 9, 283 



Weight of the starboard anchor and stock do 2, 760 



Weight of the port anchor and stock do 1,950 



Total weight of both anchors and chains do 28, 737 



Weight of the steam capstan windlass, complete do 9, 000 



The engine makes from 275 to 325 revolutions per minute ; at 300 

 revolutions the velocity of the starboard chain would be 4 fathoms per 

 minute and the port chain three and four tenths (3.4) fathoms per min- 

 ute. 



STEAM STEERING GEAR. 



The steam steering gear, known as the " steam quartermaster," was 

 built by the Pusey & Jones Company according to the patents and 

 design of Mr. Andrew Higginson, of Liverpool, England. The machine 

 may be shifted from steam to hand power by the motion of a clutch, 

 and the same wheel is used for steering by steam as by hand. Like 

 other improved steam steerers the valve is arranged to reverse the en- 

 gine by changing the ports, and an automatic arrangement is provided 

 to bring the valve to its middle position (and stop the engine) by gear- 

 ing from the engine itself. 



There are three half-trunk,, oscillating, single-acting steam cylinders 

 arranged at angles of 120 degrees from each other, all acting on tile same 

 crank pin, after the " brotherhood " system. The cylinders are 4| inches 

 diameter and 5-inches stroke of piston. On the crank shaft is a toothed 

 pinion which gears into a spur-wheel; on the shaft of the spur-wheel is 

 keyed a second pinion- wheel which gears into a second spur-wheel, 

 making the ratio of gearing nearly 36. The second pinion and the sec- 

 ond spur-wheel are keyed to hollow cast-iron shafts, through which 

 the other two shafts, respectively, work. 



Motion is communicated to the tiller chains by a chain-holder (or 

 " wild-cat") similar to those used on patent windlasses. On the extended 

 portion of the upper shaft there is a screw thread on which a large nut 

 works; this nut is clutched to one of the pinions; on the forward end 

 of the same shaft is placed the steering wheel, 5 feet 4 inches in diam- 

 eter. 



The motion of the steering wheel communicates like motion to the 

 clutch-nut, which, in turn, imparts motion to the slide-valve of the en- 

 gines ; and the motion of the engines, transmitted through the gearing 

 described, revolves the clutch-nut upon its thread in the opposite direc- 

 tion, and brings the valye back to its central position. By this contri- 



