It is stated in many places that the first published reference to the four-colour problem (aka the four-color problem) was an anonymous article in The Athenæum of April 14, 1860, attributed to de Morgan.
I was poking around in earlier issues of The Athenæum and found this on page 726, June 10, 1854:
- Tinting maps.—In tinting maps, it is desirable for the sake of
distinctness to use as few colours as possible, and at the same
time no two conterminous divisions ought to be tinted the same.
Now, I have found by experience that four colours are necessary
and sufficient for this purpose,—but I cannot prove that this is
the case, unless the whole number of divisions does not exceed five.
I should like to see (or know where I can find) a general proof of
this apparently simple proposition, which I am surprised never
to have met with in any mathematical work. F.G.
I cannot find any mention of this item anywhere, so my question is whether this information is new.
As far as I can tell, "F.G." is not identified by the magazine. Two obvious candidates are Francis Guthrie and his brother Frederic Guthrie, who discussed the question starting in 1852. An outside possibility is Francis Galton, who was involved in the problem at a later date (see Crilly, Notes and Records of the Royal Society of London, Vol. 59, No. 3 (Sep. 22, 2005), pp.285-304). So my second question is "who was F.G."?
Added: http://arxiv.org/abs/1201.2852 Suggestions for improvement welcome.