Complex sentence: At the same time as the telegraph line was completed, a pastoral industry began to develop in central and northern Australia, with the first pastoral lease being granted in 1872; by 1911 there were over 250 such leases covering over of the Northern Territory.
Split into simpler sentences: At the same time as the telegraph line was completed, a pastoral industry began to develop in central and northern Australia. The first pastoral lease was granted in 1872, and by 1911 there were over 250 such leases covering over of the Northern Territory.