Caches and Depots. 303
Depositing Letters.- To direct Attention to the Place of Deposit. -When you make a cache in an inhabited land, for the use of a travelling party who are ignorant of your purpose, there is of course some difficulty in ensuring that their attention should be directed to the place, but that the natives should have no clue to it. If you have means of gashing, painting or burning characters, something of this sort (see fig.), they
50 yards N.N.E.
will explain themselves. Savages, however, take such pains to efface any mark they may find left by white men, entertaining thoughts like those of llorgiana in the `Arabian Nights" tale of the Forty Thieves, that it would be most imprudent to trust to a single mark. A relief party should therefore be provided with a branding-iron and moveable letters, and with paints, and they should mark the tree in many places. A couple of hours spent in doing this would leave more marks than the desultory efforts of roving savages would be likely to efface. A good sign to show that Europeans have visited a spot is a saw mark (no savages use saws) : it catches the eye directly.
A system occasionally employed by Arctic expeditions, of making a cache 10 feet true north (and not magnetic north) from the cairn or mark, deserves to be generally employed, at least with modifications. Let me therefore suggest, that persons who find a cairn built or a tree marked, so as to attract notice, and who are searching blindly in all directions for further clue, should invariably dig out and examine that particular spot. The notice deposited there may consist of no more than a single sentence, to indicate some distant point as the place where the longer letter is buried. I hope it will be understood, that the precaution of always burying a notice 10 feet true north of the cairn mark is proposed as additional to and not in the place of other contrivances for giving information. There will often arise some doubt as to