Narrative of the surveying voyages of his majesty's ships Adventure and Beagle (vol.2): between the years 1826 and 1836 : describing their examination of the southern shores of South America, and the Beagles's circumnavigation of the globe

1832. NAUTICAL REMARKS — SAIL. 115 It is not prudent for any vessel drawing more than ten feet water to remain under sail in this part of the river, while it is dark, unless a good pilot is on board ; and even the best prac- tical experience is not always a sure guide, so uncertain and fluctuating are the currents and depths of water. There are a few simple precautions, useful in such circumstances, of which I may be excused for reminding young sailors. A ground-log ought to be hove frequently, and compared with a common log ; there should be a leadsman in each chains, one, at least, of whom should sound constantly : the deep-sea lead* ought to be used now and then, even in shallow water, as a check upon the hand-lead : from the vessel's draught of water to two fathoms more than that depth, the hand-line should be marked to feet, by alternate marks of dark-coloured hair and small line : strong lanterns should be suspended under the chain-wales, near the water, but close to the ship's side ; while a careful person ought to superintend the leadsman, and occa- sionally take a line into his own hand, so that by ' plumbing the bottom himself he may ascertain how far reliance is to be placed upon the leadsman's opinion. In the Plata, as well as in many other pilot-waters, to feel the ground thus is often more useful than knowing the precise depth of water, or even the colour, or nature, of the bottom. 27th Nov. Our arrangements and observations being satis- factorily completed, a sufficient quantity of provision on board to last eight months, at full allowance, and an extra sup- ply of iron and coals for the forge, in case of any serious accident, the Beagle sailed from Monte Video ; and, after filling water near Cape Jesu Maria,-|- hastened to look after her little assistants, left near Bahia Blanco. In this trip we benefitted by the assistance of Mr. Robert N. Hamond, an early and much esteemed friend of mine, who was lent to the Beagle from H.M.S. Druid, of which he was then a mate. • Massey's is preferable t Above Monte Video, on the north shore. I 2