Fresh water being at this time the most pressing of our wants, I set off the same afternoon, with a party, to examine the lake or mere discovered from Stamford Hill.  The way to it was over low land covered with loose pieces of calcareous rock; the soil was moist in some places, and, though generally barren, was overspread with grass and shrubs, interspersed with a few clumps of small trees.  After walking two miles we reached the lake, but to our mortification the water was brackish and not drinkable; the distance, besides, from Port Lincoln was too great to roll casks over a stony road.  This piece of water was named Sleaford Mere.  It is one mile broad, and appeared to be three or four in length.  The shore was a whitish, hardened clay, covered at this time with a thin crust, in which salt was a component part.  The sun being too near the horizon to admit of going round the mere, our way was bent towards the ship; and finding a moist place within a hundred yards of the head of the port, I caused a hole to be dug there.  A stratum of whitish clay was found at three feet below the surface, and on penetrating this, water drained in, which was perfectly sweet though discoloured; and we had the satisfaction to return on board with the certainty of being able to procure water, although it would probably require some time to fill all our empty casks.

SATURDAY 27 FEBRUARY 1802

Early in the morning a party of men was sent with spades to dig pits; and the time-keepers and astronomical instruments, with two tents, followed under the charge of Mr. Flinders.  I went to attend the digging, leaving orders with Mr. Fowler to moor the ship and send on shore empty casks.  The water flowed in pretty freely, and though of a whitish colour, and at first somewhat thick, it was well tasted.  Before the evening the observations for the rates of the time-keepers were commenced; and the gunner was installed in the command of a watering party, and furnished with axes to cut wood at such times as the pits might require to be left for replenishing.

The necessary duties being all set forward under the superintendance of proper officers, I employed the following days in surveying and sounding.  The direction of the port was too remote from the meridian to obtain a base line from differences of latitude, which, when observed in an artificial horizon, and at stations wide apart, I consider to be the best; nor was there any convenient beach or open place where a base line could be measured.  It was therefore attempted in the following manner:  Having left orders on board the ship to fire three guns at given times, I went to the south-east end of Boston Island with a pendulum made to swing half-seconds.  It was a musket ball slung with twine, and measured 9.8 inches from the fixed end of the twine to the centre of the ball.  From the instant that the flash of the first gun was perceived to the time of hearing