If you wanted to buy a pre-1921 edition of the Royal Geographic Society’s Hints to Travellers Scientific and General, I’m afraid you’d be completely out of luck today. Only a single copy of the 1921 10th edition is on offer at the present time at all. though you can buy it at three different prices, depending on the book search venue chosen: $57.66 (Bibliophile) or $63.70 (Choose) or $72.94 (Amazon UK).
Or you can read it on your PC, right here, for free.
The Archive.org stream isn’t as fast over satellite modem as one would like, but it is surprisingly readable and the user interface is simple and intuitive.
Hat tip to John Murrell via Karen L. Myers.