Macquarie Island, a busy station in the days of the early sealers, had become almost neglected. Little accurate information was to be had regarding it, and no reliable map existed. A few isolated facts had been gathered of its geology, and the anomalous fauna and flora sui generis had been but partially described. Its position, eight hundred and fifty miles south-south-east of Hobart, gave promise of valuable meteorological data relative to the atmospheric circulation of the Southern Hemisphere and of vital interest to the shipping of Australia and New Zealand.
As to the Antarctic sphere of work, it has been seen that very little was known of the vast region which was our goal. It is sufficient to say that almost every observation would be fresh material added to the sum of human knowledge.
In addition to the work to be conducted from the land bases, it was intended that oceanographic investigations should be carried on by the 'Aurora' as far as funds would allow. With this object in view, provision was made for the necessary apparatus which would enable the ship's party to make extensive investigations of the ocean and its floor over the broad belt between Australia and the Antarctic Continent. This was an important branch of study, for science is just as much interested in the greatest depths of the ocean as with the corresponding elevations of the land. Indeed, at the present day, the former is perhaps the greater field.
The scope of our intentions was regarded by some as over-ambitious, but knowing
How far high failure overleaps the bound
Of low successes,
and seeing nothing impossible in these arrangements, we continued to adhere to them as closely as possible, with what fortune remains to be told.
To secure a suitable vessel was a matter of fundamental importance. There was no question of having a ship built to our design, for the requisite expenditure might well have exceeded the whole cost of our Expedition. Accordingly the best obtainable vessel was purchased, and modified to fulfil our requirements. Such craft are not to be had in southern waters; they are only to be found engaged in Arctic whaling and sealing.
The primary consideration in the design of a vessel built to navigate amid the ice is that the hull be very staunch, capable of driving into the pack and of resisting lateral pressure, if the ice should close in around it.
So a thick-walled timber vessel, with adequate stiffening in the framework, would meet the case. The construction being of wood imparts a certain elasticity, which is of great advantage in easing the shock of impacts with floating ice. As has been tragically illustrated in a recent disaster, the ordinary steel ship would be ripped on its first contact with the ice. Another device, to obviate the shock and to assist in forging a way through the floe-ice, is to have the bow cut away below the water-line. Thus, instead of presenting to the ice a vertical face, which would immediately arrest the ship and possibly cause considerable damage on account of the sudden stress of the blow, a sloping, overhanging bow is adopted. This arrangement enables the bow to rise over the impediment, with a gradual slackening of speed. The immense weight put upon the ice crushes it and the ship settles down, moving ahead and gathering speed to meet the next obstacle.
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