Original sentence: In New South Wales, Australia, Train Controllers and the Telephone Train Control System have survived to the present despite the advent of power signal boxes and other improved technical provisions for Signalmen.It is difficult to ascertain whether these changes have led to an overall improvement in train working efficiency or were simply effected in the name of perpetuating the Train Controller's profession
Edited sentence: In New South Wales, Australia, Train Controllers and the Telephone Train Control System have survived to the present, despite the advent of power signal boxes and other improved technical provisions for Signalmen.It is difficult to ascertain whether these changes have led to an overall improvement in train working efficiency on a colonial network with twenty first century traffic, or were primarily effected in the name of perpetuating the Train Controller's profession