70 True Time. 



except in exact unison with the controlling one. Even if 

 its tendency was to lose or gain many minutes a day it can- 

 not do it, and it would continue to show the same second as 

 the Observatory clock so long as the currents along the time- 

 main continued. The great advantage of this method is 

 that even should any failure take place in the Observatory 

 clock or in the currents, the clocks would continue to go as 

 well as before adopting the control, but being governed only 

 by their own pendulums would be liable to the losing or 

 gaining rate belonging to them. 



To carry this method into practice in Melbourne it would 

 be necessary to lead another wire on the telegraph posts 

 already erected to such parts of the city as it is likely to be 

 required — certainly to the railwa}^ stations. Post-office, 

 Telegraph- office, and, perhaps, other public buildings. This 

 would not cost much — a couple of hundred pounds would 

 probably do it for the whole city. A small rent for the use of 

 the time supply could be charged, which I feel confident would 

 be readily paid, and which would render good interest on 

 the outlay. The new pendulum bobs and magnets could be 

 easily made and fixed by any intelligent mechanic, according 

 to a pattern which would be generally adopted. Those 

 using the control would have nothing to do with batteries, 

 nor would they have any trouble beyond keeping the wires 

 intact. 



If this plan should be carried out, and I hope and believe 

 it will, we should, instead of the state of public time-keeping 

 I alluded to at the commencement, have all the clocks con- 

 trolled, showing identically the same time, and all correct to 

 a second. In Glasgow, as an extra security to the public, it 

 is made a sine qua non that those using the supply should 

 have a small, simple, galvanometer beside their clock, which 

 shows by right and left deflections of its needle the alter- 

 nating currents, and also by an omitted deflection at the 

 sixtieth second of each minute, if the controlled indicates the 

 same second as the Observatory clock. The heavy two 

 seconds pendulum of large turret clocks can be just as readily 

 controlled by the same main, by a different disposition of the 

 permanent magnets. I am not aware that any method of 

 controlling half seconds pendulums in this manner has yet 

 been devised, but I am now engaged in some experiments 

 on controlling, and I think a method applicable to half 

 seconds pendulums, with the same currents, can be arranged. 



