The second warning concerned grave international matters. European politics were in the unsettled condition which, after the illusive international courtesies of the Great Exhibition of 1851, ended in the Crimean War, and it was feared that in the event of hostilities breaking out, the zeal of the officers for their country might tempt them to transcend their peaceful occupation. The instructions with regard to this ran as follows: "In the event of this country being involved in hostilities during your absence, you will take care never to be surprised; but you are to refrain from any act of aggression towards the vessels or settlements of any nation with which we may be at war, as expeditions employed on behalf of discovery and science have always been considered by all civilised communities as acting under a general safeguard." The great scientific expeditions sent out in recent times by the governments of Britain, Germany, and the United States, were fitted with every convenience for the staff of naturalists, and the luxuries and comforts of civilisation attended them round the world. The late Professor Mosely, for instance, who was a naturalist on the English _Challenger_ expedition, told the present writer of a pleasant way in which a peculiarity of the deep sea was made to pay toll to the comfort of those on board ship. The great ocean depths all over the world, under the burning skies of the tropics, or below the arctic ice-fields, are extremely cold, the water at the bottom always being only a few degrees above freezing point. When the dredge brought up a sample of the abysmal mud at a convenient time, it was used to ice the wine for the officers' mess. There was, however, no cooled champagne for Huxley.