The spring floods of the Tobol and Irtysh rivers had been particularly severe that year, and some of the local peasants blamed the foreigner with his strange equipment who was "messing with the Sun": Chappe had to be protected by a cordon of armed Cossacks to make his observations.

He published his results from Saint Petersburg (Mémoire du passage de Vénus sur le soleil, avec des observations sur l'astronomie et la déclinaison de la boussole faites à Tobolsk, en Sibérie), and didn't return to France until 1763.

The text is hardly a flattering description of the country, and an anonymous pamphlet (Antidote ou Réfutation du mauvais livre superbement imprimé intitulé : Voyage en Sibérie, etc.)

Chappe and physicist Henri-Louis Duhamel du Monceau (1700–82) were selected to test one such chronometer, made by Swiss watchmaker Ferdinand Berthoud (1727–1807) on board the corvette L'Hirondelle in 1764.

For the transit of Venus on 3 June 1769, Chappe's destination was the Mission of San José del Cabo at the tip of the Baja California peninsula in modern-day Mexico.

As well as the contributions his observations of the transits of Venus gave to solving the problem of the size of the solar system, his nephew, Claude Chappe was greatly inspired by reading Voyage en Sibérie.