The First Mixed Commission apparently did not hold any formal meeting after 19 January 1907. It must not be forgotten that, at the time when such a meeting might have been held for the purpose of winding up the work of the Commission, attention in both countries, on the part of those who were specially qualified to act and speak on their behalf in these matters, was directed towards the conclusion of the Treaty of 23 March 1907. Their chief concern, particularly in the case of Colonel Bernard, could hardly have been the formal completion of the results of the delimitation they had carried out.

The final stage of the operation of delimitation was the preparation and publication of maps. For the execution of this technical work, the Siamese Government, which at that time did not dispose of adequate means, had officially requested that French topographical officers should map the frontier region. It is clear from the opening paragraph of the minutes of the meeting of the first Mixed Commission on 29 November 1905 that this request had the approval of the Siamese section of the Commission, which may indeed have inspired it, for in the letter of 20 August 1908 in which the Siamese Minister in Paris communicated to his Government the eventual results of this work of mapping, he referred to "the Mixed Commission of Delimitation of the frontiers and the Siamese Commissioners' request that the French Commissioners prepare maps of various frontiers". That this was the deliberate policy of the Siamese authorities is also shown by the fact that in the second (1907) Mixed Commission, the French members of the Commission were equally requested by their Siamese colleagues to carry out cartographical work, as can be seen from the minutes of the meeting of 6 June 1908.

The French Government duly arranged for the work to be done by a team of four French officers, three of whom, Captains Tixier, Kerler and de Batz, had been members of the first Mixed Commission. This team worked under the general direction of Colonel Bernard, and in the late autumn of 1907 it completed a series of eleven maps covering a large part of the frontiers betsveen Siam and French Indo-China, including those portions that are material in the present case. The maps were printed and published by a well-known French cartographical firm, H. Barrere.

The eleven maps were in due course communicated to the Siamese Government, as being the maps requested by the latter, and the Court will consider later the circumstances of that communication and the deductions to be drawn from it. Three of the maps had been overtaken by events, inasmuch as the former frontier areas they showed had, by virtue of the Treaty of March 1907, now become situated wholly in Cambodia. Siam was not therefore called upon either to accept or reject them. Her interest in the other maps remained. Amongst these was one of that part of the Dangrek range in which the Temple is situated, and on it was traced a frontier line purporting to be the outcome of the work of delimitation and showing the whole Preah Vihear promontory, with the Temple area, as being on the Cambodian side. If therefore the delimitation carried out in respect of the Eastern Dangrek sector established or was intended to establish a watershed line, this map purported to show such a line. This map was filed by Cambodia as Annex 1 to its Memorial, and has become known in the case (and will be referred to herein) as the Annex 1 map.

It is on this rnap that Cambodia principally relies in support of her claim to sovereignty over the Temple. Thailand, on the other hand, contests any claim based on this map, on the following grounds: first, that the rnap was not the work of the Mixed Commission, and had therefore no binding character; secondly, that at Preah Vihear the map embodied a material error, not explicable on the basis of any exercise of discretionary powers of adaptation which the Commission may have possessed. This error, according to Thailand's contention, was that the frontier line indicated on the map was not the true watershed line in this vicinity, and that a line drawn in accordance with the true watershed line would have placed, and would now place, the Temple area in Thailand. It is further contended by Thailand that she never accepted this map or the frontier line indicated on it, at any rate so far as Preah Vihear is concerned, in such a way as to become bound thereby; or, alternatively that, if she did accept the map, she did so only under, and because of, a mistaken belief (upon which she relied) that the map line was correctly drawn to correspond with the watershed line.

The Court will, for the moment, confine itself to the first of these contentions, based on an argument which the Court considers to be correct, namely that the map was never formally approved by the first Mixed Commission as such, since that Commission had ceased to function some months before the production of the map. The record does not show whether the map and the line were based on any decisions or instructions given by the Commission to the surveying officers while it was still functioning. What is certain is that the map must have had a basis of some sort, and the Court thinks there can be no reasonable doubt that it was based on the work of the surveying officers in the Dangrek sector. Being one of the series of maps of the frontier areas produced by French Government topographical experts in response to a request made by the Siamese authorities, printed and published by a Paris firm of repute, all of which was clear from the map itself, it was thus invested with an official standing; it had its own inherent technical authority; and its provenance was open and obvious. The Court must nevertheless conclude that, in its inception, and at the moment of its production, it had no binding character.

Part 9