West prospective view of Portsmouth harbour. The National Gazetteer of 1868 reported 'Portsea Island, on which Portsmouth stands, is separated from the main land by a narrow inlet at its northern extremity. Portsmouth harbour, which is on the W. side of it, is entered by a narrow creek at the S., defended by Southsea Castle and Monckton Fort. The narrowest part is at Portsmouth Point, a little higher, where the width is only 220 yards. The basin of the harbour measures about 3 miles each way, and contains three channels, leading to Porchester, Fareham, and the N. of Portsea Island. The depth is sufficient to accommodate men-of-war of all sizes, even at low tide'. This original drawing is on of two sketches which form the basis for a later engraving entitled 'The West Prospect of Portsmouth, in Hampshire', made by Samuel and Nathaniel Buck on 11 September. This drawing also shows the landmark buildings of Portsmouth have been numbered, in preparation for the key of the later engraving.