1783 - Steamboat Le Pyroscaphe

Always looking for a solution of river navigation substituting for the horse-drawn barges, Claude de Jouffroy d’Abbans is back in competition after seven years of reflections and of design. He trials a new steamboat moving on the Saône river in the city of Lyon. By all accounts, this is a feat.  There have been at least ten thousands eye witnesses to admire the boat when, for the great event, it triumphantly steamed against the stream from Vaise, the place where it had been built, to Barbe island, 1½ mile away at an apparent speed of five or six knots. Well, the engine has failed there…

Many persons have seen Le Pyroscaphe departing from the cathedral, half a mile downstream which seems likely. There may be some confusion in witness’ mind between the great demonstration and the rehearsal around Vaise. The trial has been ascertained by the crowd but, strange enough for such a decisive matter, it seems that nobody thought of establishing the minutes in due form.

The boat, 140-foot long and 14-foot wide is a full scale prototype. Loaded, it displaces about 160 tons. It is propelled by two paddle wheels driven by a two-24”-cylinder single-acting Newcomen engine. The two cylinders act in phase opposition so as to soften motion.

¤ Note that there is no fly wheel but the phase-opposition gear works correctly.

Jouffroy has invented a rather complex drive chain – complex and flimsy. Movement is transformed by a frame fitted with pawls which engage in a gear wheel on the axis of the paddle wheels, and fade on their way back. Tricky though, this is the weak point of the new design which is sound otherwise. Boat size is consistent with lock size on main rivers. Its speed is impressive. Of course, nobody has ever seen such a thing. We may think that Jouffroy even forced the machinery to emphasise fastness of his boat and impress the public, hence the breakdown in the end of demonstration.

Jouffroy has been supported by an eminent master smith, Antoine Frèrejean. This new experiment has absorbed the whole capital of Jouffroy’s company – the same company as in 1776, of which he has indeed become the majority shareholder when Auxiron died in 1778. Monnin and Auxiron’s heirs delivered him the papers, notes and calculations worked out by Auxiron who encouraged Jouffroy up to his last day. It has taken seven years but it seems that Jouffroy now holds on his business.

The hero of the day expects to be granted the famous and still pending 15-year privilege promised to the one who could prove steamboat feasibility. He writes down his report to the secretary-of-state, claiming a full success ascertained by a crowd of witnesses. But Paris is far from Lyon. In return, he receives a letter from Charles-Alexandre de Calonne, 49 years old, Controller-General of Finances, requiring a trial in Paris under the control of the Académie Royale des Sciences. Everything must be repeated from a new base. From whom can he find fresh money to comply with this ?

¤ It has been said that Jouffroy would also be obliged to give the new prototype a scale multiplied by three with 500 tons, which is clearly outsize and meets no genuine industrial requirement.

This specification does not appear in Calonne’s letter. Is it part of an enclosure ? Examiners appointed by the Académie des Sciences are two brilliant engineers : Jean-Charles de Borda, 50 years old, a scholar and a complete gentleman by all records, deeply involved in the questions of celestial navigation, and Jacques-Constantin Périer, 41, a complete businessman, briefly involved in steamboat development in 1774-75 around Claude-François-joseph d'Auxiron (†1778) as we already know but still involved in steam engine business. Have they reinforced criteria ? And for what purpose ? Are there documents that would enlighten the question ?

The secretary-of-state may rightly consider that the experiment has been convincing but not probative – too short and lacking scientific and administrative rigour for sure. One may nevertheless object about Paris and about tonnage should that 500-ton requirement be true. As it is, Le Pyroscaphe seems to comply with real business constraints but the drive chain, questionable – which leads to suspicion of unfair requirements prescribed by a rival to avoid any repetition of the successful trial. It is impossible to deny or ascertain.

This time, Jouffroy is down.   He is obsessed by this privilege which escapes to him once more. It does obstruct the horizon of his thinking.

__________

LINKS WITH PREVIOUS CHRONICLES

1773 - French Belief in Steamboats

1776 - Steamboat Le Palmipède

__________

IN RETROSPECT FROM TODAY

NOTE - About Jouffroy.

He will never recover from that failure. He will nevertheless launch in 1816 an ephemeral business of navigation on the Seine river between Paris and Montereau. He names Charles-Philippe, after the king’s brother, this ultimate steamboat which is not too late, forty years after Le Palmipède, as things will not have evolved very much.

__________

SUGGESTED BIBLIOGRAPHY

Louis Figuier – Les Merveilles de la Science, tome 1, Deuxième Section : Les Bateaux à Vapeur – Paris, 1867 - available on the internet

__________

CREDIT

Elisabeth Louise Vigée-Lebrun - Portrait of Calonne - oil on canvas, circa 1780 - © Royal Collection, London