The plans had been made, about half the funding had been subscribed, and a ship had been purchased when the project was disrupted by the Franco-Prussian War in 1870.

[1] Gustave attended the Collège de Bourg, where he is recorded as a pupil of elementary mathematics in 1842[1] He was admitted to the École Polytechnique in 1843.

[10] He was in charge of rough and undisciplined seamen in difficult and poorly charted waters, but found time to compose a paper on the Lois de l'insolation (Laws of solar irradiance) which was communicated in abbreviated form to the Academy of Sciences on 28 January 1867.

He also observed that icebergs were born on land and died in the ocean, while ice fields were formed and dissolved at sea.

[11] He outlined his plan later, for an expedition with about 15 sailors and scientists:[11] One would have to leave in the winter, and reach the Pacific Ocean by way of Cape Horn or the Cape of Good Hope, cross the ocean from south to north, pass the Bering Straits, reach the Polynya, open water found recently by the navigators Herold and Plower.

[11]Samuel Richard Van Campen wrote in 1878 of the plan, It was conceived, it is only just to say, in complete ignorance, as M. Malte-Brun tells us, of the projects of Osborn and Petermann, and the ground over which it would be necessary to proceed was suggested to the projector by the sight of the thin ice covering the Polar Sea to the north-west of Behring's Straits, about 73° N., promising apparently a passage to the mariner bold enough to advance right through it, together with the appearance of the physical state of the sea in those high latitudes, the probable effect of insolation, and, finally, the information he was able to draw from the scattered traditions of Arctic navigators.

[15] Lambert described the whole history of Arctic exploration, gave the scientific grounds for his plan, and described the importance of a French expedition through the Bering Straits.

He insisted that there was open sea to the northwest of the straits in the direction of the Pole, and said that insolation during the Arctic summer and favorable currents would make it possible to avoid the barriers of broken ice that had blocked the passage in the past.

[15] On 20 December 1867 Lambert spoke at more length to the Société de géographie and described his plans for the proposed polar voyage and the research he wanted to undertake.

[5] He presented his plan in other parts of France, for example to an audience of 4,000 people in the hall of the Bourse de Bordeaux on 19 February 1868.

[20] August Heinrich Petermann, director of the Gotha Geographical Review, wrote from Germany to the Société de géographie expressing his approval of the plan.

Lambert tried to engage the public imagination by floating a huge airship, the Pôle Nord, from the Champ de Mars.

[24] He published a circular in which he announced that the Boreal was waiting to leave from the Vauban basin at Le Havre, and could depart in a matter of weeks rather than months.

[23] At the start of December 1870 he turned down the title of Colonel of the Veterans of the National Guard, and enlisted with the 119th Infantry Regiment.