But further evidence from an unquestionable source is available as to date. The charts in du Halde's "China" were engraved between the years 1729 and 1734, and all but the general maps were completed prior to 1733. The date 1732 is assigned by d'Anville's colleague to the map of Bering's journey. Of these maps it is further said:
"They form what is commonly known as d'Anville's Atlas of China. Nevertheless this geographer did not participate equally in the production of all. The detailed maps (of which the Bering map is one) were furnished by the Jesuits and he only supervised the engraving, but the general charts were entirely the work of d'Anville, who reconstructed and amplified them from all possible sources. They were reproduced at Hague under the title 'New Atlas of China,' etc., by M. d'Anville."
These statements of d'Anville's colleague, M. Barbic du Bocage, are thus verified by du Halde, page lxix:
"Pour les Cartes Générales, nous y avons peu touché & celle du Voyage du Capitaine Beerings paroit sans le moindre changement."
In the Russian atlas, 1745, the explanatory text regarding map 19, whereon appears the extreme northeastern coast of Siberia and the greater part of Kamshatka, runs as follows:
"We have determined the location of these provinces in part by astronomical observations which have been made there, and in part upon certain geographical and hydrographic maps which have been transmitted to us."
So far as Kamshatka and the Bering strait regions go, it is reasonable to believe that this chart, since it was published by the Royal Academy of Sciences, is substantially a reproduction of the map transmitted to the Academy by de l'Isle in 1732, especially as this geographer was employed for about thirteen years in amassing data for the atlas in question.
The writer has very carefully compared the chart of Kamshatka and adjoining regions as published in d'Anville's atlas of 1736, in the Russian atlas of 1745, and in the de l'Isle chart of 1752. From comparisons he is led to believe that these maps have substantially the same basis—that is, the chart prepared by de l'Isle in 1732 for the Academy of Sciences, St. Petersburg. In this connection the criticism of the Russian officer is significant. He says: "I will now finish with a general observation about the part of Siberia that we see on M. de l'Isle's chart (1752). It is simply a copy of the Russian atlas (1745), without even corrections of the errors of drawing and writing which have crept into that work." Elsewhere he adds: "We can correct the error of M. de l'Isle, who places Bering island at 54 degrees, only a short distance from Avatscha, whereas it is on the 56th parallel, 60 miles off Avatscha and 40 Dutch miles from the mouth of the Kamschatka river."
It is worthy of note that on Bellin's map of 1749(?) Bering island is crossed by the 56th parallel of latitude, and that along the southern edge of the Arctic ocean is a route track, marked "Voyage fait par Mer en 1648 par 3 vaisseaux Russiens dont un est parvenu a la Kamtschatka." On de l'Isle's chart of 1752 also appears the route of 1648, but Bering island is in latitude 54°. As to the position of Bering isle, the truth, as the Wise Man tells us is oft the case, abides between the two, as the 55th parallel intersects the land in question. At Cape Shelagskoi, d'Anville, 1737, the Russian atlas of 1745 and the de l'Isle of 1752 agree in charting four islands northeast of the cape instead of two islands to the west. This indicates a common origin to the charts, and where else can it be ascribed than to the de l'Isle map of 1732? The Russian officer, however, gives a clue as to the date when work on the map was commenced. He says: