The entrance to the harbour of Aberdeen is naturally bad, owing to a bar at the mouth of the river, where, at ebb-tide, the depth of water was often not more than two feet. To remedy this evil was, from a very early period, the ardent desire of the citizens, and to some of their first efforts in this direction we have alluded in our notice of Aberdeen Light-house. But it is since the commencement of the seventeenth century that the most effective improvements have been made, amongst which we may name the erection of a bulwark on the south side of the entrance, and the removal of a great stone, called "Knock-Maitland," which lay nearly in the middle of the river, both of which were accomplished in succession; the first in 1608, and the latter in 1618. Between 1623 and 1658, the quay was extended eastward, towards Futtie; by which means a considerable portion of ground was redeemed below the Castle-hill, and is now covered with buildings. In 1755 an additional quay was built a good way further down, opposite the village of Torrie. In 1770, further improvements were projected; and, on a report from Mr. Smeaton, recommending the erection of a pier on the north side of the entrance, so that the influx of sand from the north might be prevented, and the removal of the _bar_ effected, by confining the waters of the river Dee within narrower bounds, the work was commenced in 1775, and finished in less than six years. The length of this pier was twelve hundred feet, and it terminated in a round head of sixty feet in diameter. Owing, however, to a departure from Mr. Smeaton's plan, by which the pier was founded too far to the north, it was found that a heavy swell entered the harbour; and to obviate this formidable inconvenience, a bulwark was projected from the pier, to about one-third across the channel.