TKANSACTIONS OF SECTION G. 735 



triple concentric cable, of which the outers had a cross-section of 05 square inch 

 and the neutral 0'25 square inch. The feeder was one mile in length. 



The second instrument was intended for determinations of amperes, volts, 

 •watts, and power factor. It was constructed on the hot-wire principle, and was 

 intended for use in test-rooms, workshops, &c. The various determinations were 

 made by taking readings with a plug attached to the instrument in diSerent plug- 

 holes, two readings being necessary for the determination of watts. 



The third instrument was styled a ' fault indicator,' being designed principally 

 for use on tramway circuits. The circuit-breakers protecting tramway feeders 

 often open for unknown causes : sometimes it may be due to faults occurring, 

 sometimes merely temporary overload. Usually the circuit-breakers are closed 

 again without further precaution. This is obviously an unsatisfactory proceeding. 

 The fault indicator showed whether the line was ' clear ' or ' blocked ' by measuring 

 its resistance. It was arranged on the principle of a bridge : if the resistance was 

 below a certain amount the pointer of the indicator went hard over to the left, 

 indicating ' line blocked ' ; if above a certain limit, bard over to the right, indicating 

 ' line clear.' 



The fourth instrument was a synchronising switch and voltmeter. 



The switch was arranged so that with a single setting it — 



(1) put pUot synchronising lamps into the circuit, which lamps were situated 

 near the engine of the incoming alternator for the driver's benefit ; 



(2) put synchronising lamps into circuit on the panel of the incoming 

 alternator ; 



(3) put a synchronising voltmeter in circuit ; 



(4) put a special voltmeter into circuit witli a double winding, eacb winding 

 actuating an independent pointer. 



The two pointers, however, moved over the same dial, and were arranged so 

 that if they were indicating equal voltage they together formed a radial line 

 across the "dial ; if unequal, a broken line. The one winding was connected to 

 the incoming alternator, the other to the 'bus bars. The double voltmeter and 

 the synchronising voltmeter were mounted on the same swinging bracket. With 

 the arrangement described the ordinary general arrangement of the switchboard 

 could be simplified, and the process of synchronising facilitated. 



5. The Science of the Workshop. By "VV. Taylor, 



6, The Importance of Minor Details in Engineering Work. 

 By M. HoLROYD Smith. 



7. On the Specific Utilisation of Materials in Dynamo Construction. 

 By Professor S. P. Thompson, F.R.S. 



8. A new Flashing Lighthouse Light tvithout Intervals of Darkness. 



By J. E-. WiGHAM. 



9. A Joint Discussion with Section L on the Training of Engineers. 



TUESDAY, SEPTEMBER 16. 

 The following Report and Papers were read : — 



1. Report on the Small Screw Gauge. — See Reports, p. 350. 



