ANNIVERSARY ADDRESS. 35 
a time being in any section. This is accomplished on double 
lines by what are called ‘“‘ block instruments,” by which means a 
telegraphic communication is established between each section, and 
the various signals such as ‘line clear,” “train on line,” or other 
information as to the description or position of each train is given 
from one box to another. The instruments consist of movable 
lettered discs and bells, and are worked under a special code of 
_ “beats on the bell,” or otherwise. On the single line, where the 
risk of collision is obviously increased, and where greater pre- 
cautions are necessary, other means are adopted, such as the 
“ staff and ticket,” “electric staff,” and “electric tablet,” which | 
ensures that no engine or train shall leave one station for another 
unless the driver is in possession of either a wood or metal staff, 
a ticket, or a metal disc or tablet. 
When the Commissioners took office they at once saw the 
necessity for improving the primitive method of working the 
trafic. The increase of traffic, and the necessity for providing 
greater means of safety, has led within the last few years to the 
adoption of more modern safety appliances, with the result that 
the ‘absolute block system” on double lines has been extended 
over the whole of the passenger lines, increasing from twenty-eight 
miles at the end of 1888, to one hundred and fifty-two miles at 
the present date; while on single lines the electric staff and 
tablet, which are both also absolute blocks, has been provided 
over seven hundred and twenty-two miles of line, superseding the 
old staff and ticket system. ‘The lines included in these systems 
embrace the Great Southern, South Coast, and North Coast 
throughout; the Great Western as far as Dubbo, and the Great 
Northern as far as Tamworth, 
Electricity now plays an important part in the safe working of 
the railway. This is effected under an electric system of working 
the tablet or electric staff. The authority an engine-driver has 
to obtain before he can proceed on a section is either a metal 
tablet or staff, taken from a machine controlled by electricity ; 
each section of the line, which may be ten miles more or less in 
