Some allowance must be made for the needs of the 'auxiliaries,'[96] the vessels that bring supplies and in other ways attend on the fighting ships. This may be put at 7 per cent. The tonnage required would accordingly amount in all to about 9000. [Footnote 96: The 7 per cent. mentioned in the text would probably cover nearly all the demands--except coal--of auxiliaries, which would not require much or any ammunition. Coal is provided for separately.] The squadron would burn in harbour or when stationary about 110 tons of coal a day, and when under way about 1050 tons a day. For 140 harbour-days the consumption would be about 15,400 tons; and for 43 days under way about 45,150: so that for coal requirements we should have the following:-- Harbour consumption 15,400 tons. Under-way consumption 45,150 " ------ Total for fighting ships 60,550 " 7 per cent. for auxiliaries (say) 4,250 " ------ Grand total 64,800 " Some time ago (in 1902) a representation was made from the China station that, engine-room oil being expended whenever coal is expended, there must be some proportion between the quantities of each. It was, therefore, suggested that every collier should bring to the squadron which she was supplying a proportionate quantity of oil. This has been approved, and it has been ordered that the proportions will be 75 gallons of oil to every 100 tons of coal.[97] It was also suggested that the oil should be carried in casks of two sizes, for the convenience of both large and small ships. [Footnote 97: I was informed (on the 10th December 1902), some time after the above was written, that the colliers supplying the United States Navy are going to carry 100 gallons of oil for every 100 tons of coal.] There is another commodity, which ships have never been able to do without, and which they need now in higher proportion than ever. That commodity is fresh water. The squadron constituted as assumed would require an average of about 160 tons of fresh water a day, and nearly 30,000 tons in six months. Of this the ships, without adding very inconveniently to their coal consumption, might themselves distil about one-half; but the remaining 15,000 tons would have to be brought to them; and another thousand tons would probably be wanted by the auxiliaries, making the full six months' demand up to 16,000 tons.