At an early hour the next morning we got under weigh, and glided down Loch Ness, which is twenty-four miles long, and about a mile and a quarter broad, although it is narrower in some places.  The depth is very great, in some parts one hundred and thirty fathoms.  In consequence of this the water seldom freezes in the loch.  The rugged and heath-covered mountains rise on either side to the height of about a thousand feet; and frequently we saw growing on them forests of oak, ash, elm, and other trees, with a thick underwood of hazel and holly intermingled with a profusion of wild roses.