48 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [46] 



toward the central part of the head, with some jar, slipping back at the 

 same time. The loss of power due to this slip, plus the power required 

 to overcome the stiffness of the rope in bending it on the head, will be 

 found by taking the difference between the net power applied to the 

 revolution of the gypsy head and the power indicated by the dynamom- 

 eter. 



The diameter of the smallest part of the gypsy head is 22i| inches, and 

 the diameter of the wire rope is three-eighth of an inch, consequently the 

 velocity of the rope, per revolution of the head, supposing there were 



(22— + §\ 

 — 1 -jk — J =6.104 feet,* but from 



the reading of the register it is only 5. 924 feet. 



The following record is from the mean of a number of observations 

 made by the writer and assistants: 



Velocity of the rope indicated by the register, in feet, per minute 148. 600 



Velocity of the rope due to the smallest diameter of the gypsy head 153. 100 



Tension on the wire, in pounds, indicated by the dynamometer 2, 737. 5 



Revolutions of the gypsy head per minute 25. 085 



Revolutions of the engine per minute 107. 500 



Indicated horses-power developed by the engine 15. 563 



Indicated horses-power required to work the engine 1.453 



Horses-power absorbed by the friction of the load 1. 167 



Net horses-power applied to the tension on the rope 12. 943 



Horses-power accounted for by the dynamometer 12. 327 



Horses-power absorbed by the slipping and bending of the rope on the gypsy 

 head 616 



The 15.563 horses-power indicated by the engine is divided as fol- 

 lows : 



Per cent. 



For pulling in the rope 79.207 



For working the engines 9. 335 



For overcoming the friction of the load 7. 500 



For overcoming the slip and bending of the rope 3. 958 



100. 000 

 REELING ENGINE. 



The reeling engine, Plate XXY, was built by Copeland & Bacon, 

 of New York, and is of the same character of design as the dredging 

 engine. Its object is to stow the wire rope, and to keep a limited ten- 

 sion on that rope when in motion. It is essentially a wrought-iron, 

 built-up drum, mounted on a horizontal axis, driven by a double-cylinder 

 half-trunk steam-engine, through the intervention of toothed gearing 

 and a friction clutch. It has a friction brake to regulate the paying out. 



It is provided with a traveling guide, mounted in front of the drum, 

 for guiding the rope smoothly and uniformly upon the drum. The 

 guide is actuated by a double screw, with equal right and left pitches, 



*This is on the assumption that the rope travels on a radius due to that of the gypsy 

 head plus its own radius, which has been proved by the passage of the same wire 

 over our register sheave. 



