An 'unearned increment,' such as would satisfy the most glowing dreams of the most ardent speculator, has occurred in the capital. One instance may be given. One of the few original half-acre blocks now in possession undisturbed--not cut up--of the family of the original purchaser is situated in a good part of Collins Street. The colonist whose executors are now holding the property gave £20 for it in 1837. To-day the sixty-six feet frontage to Collins Street is worth £1,150 per foot; the Flinders Lane frontage is worth £350 per foot. A little ciphering brings out a sum total of £99,000 as the present value of the original £20 investment. And for decades the income derived from the block has been counted by many thousands per annum. The £20 has by this time earned at least £200,000 in all. In many country places a £5 lot will bring £500 when a decade has passed. But then the place may not become a centre, and your 'unearned increment' will be no more substantial than the evening cloud. There is a reverse to this shield, as to all others. [Illustration: BIRD'S-EYE VIEW OF SANDHURST.] From Melbourne it is easy to journey to the two great gold-fields of Victoria--Ballarat and Sandhurst. The latter is due north, and is reached by a double-track railway, built in the early days at a cost of £40,000 per mile. Single-track railways, costing £4,000 per mile, are now the order of the day. Sandhurst is the Bendigo of old days. It has had many ups and downs; has been deserted, and has been ruined; but the result is the fine city of to-day, with its broad, tree-lined streets, its splendid buildings, and high degree of commercial activity. As a recent writer puts it: 'What vicissitudes has not the place undergone! From enormous wealth to the verge of bankruptcy, from the pinnacle of prosperity to the direst adversity; from financial soundness to commercial rottenness; and yet, with that wonderful elasticity and buoyancy which characterises our gold-fields, the falling ball has rebounded, the sunken cork has again come to the surface, and Sandhurst, after all her reverses, is perhaps now richer and on a safer basis than ever--a city whose wide, well-watered streets are perfect avenues of trees, bordered by handsome buildings and well-stocked shops, brilliantly lighted by gas; whose hotel accommodation is proverbially good, whose civic affairs are admirably regulated, whose citizens are busy, hospitable, and prosperous.' There is no mistake about the character of the town. Miles and miles of country before you enter it have been excavated and upturned by the alluvial digger. And there are few more desolate sights to be met with than a worked-out and deserted diggings, for often Nature refuses to lend her assistance, and does not hide the violated tract with trees or verdure. Ugly gravel heaps, staring mounds of 'pipe-clay,' deposits of sludge, a surface filled with holes, broken windlasses, the wrecks of whims, all combine to make a