Tom,
    Of course regarding the matter of the basic supply and demand diagram, yes, Cournot was first, but he had the axes switched from the standard Marshallian formulation.  It was Rau who first did it the way Marshall did, as did Jenkin.  The French tradition continued to follow Cournot for a long time, most notably with Walras.
    Curiously, when we talk about it we present it as if it should done as Cournot and his followers did so, with classroom presentations almost always taking about what happens after price changes.  It is a sign of a sharp student who asks, "If price is the variable changing and quantity is responding, why do we have price on the vertical axis?"  Needless to say, most here know the answer, which is that Marshall was focused on agricultural markets, particularly the wheat one that led to the bread one, still fundamental for social welfare in UK late 19th century, and in such markets exogenous forces, notably the weather, impacting supply are a regular driving force, although he also  was well aware of the work of both Rau and Jenkin reportedly.
________________________________________
From: Societies for the History of Economics [[log in to unmask]] on behalf of Thomas Humphrey [[log in to unmask]]
Sent: Sunday, February 23, 2014 7:01 AM
To: [log in to unmask]
Subject: [SHOE] Wicksell and Stigler's Law of Eponymy

Re: Knut Wicksell and his cumulative process analysis. It occurs to me
that what economists call the "Wicksellian cumulative process" is a
perfect example of the operation of Stigler's Law of Eponymy according
to which "No scientific discovery is named for its original discoverer."

For as James Ahiakpor and others have shown in these posts, 18th and
19th century classical economists including Hume, Smith, Thornton,
Ricardo, Joplin, and others had assembled and put together elements of
the cumulative process model long before Wicksell did so in his 1898
Interest and Prices. Those classicals were the original discoverers of
the cumulative process analysis. Yet today we refer to the model as
the Wicksellian cumulative process rather than as the Hume-Thornton-
Ricardo-Joplin cumulative process.

Why? Because it was Wicksell more than his classical predecessors who
made the model sing and who put it on the map. It was Wicksell's
formulation that was most instrumental in influencing economists to
accept the model as a valid depiction of the process of price-level
change. For that reason, Wicksell gets the honor of having the model
bear his name. Stigler's Law.

The same thing happened with the ordinary microeconomic demand-and-
supply curve diagram, which today bears the label "the Marshallian
Cross" after Alfred Marshall. But it wasn't Marshall who discovered
the diagram. Rather A. A. Cournot was its original discoverer in his
1838 Researches into the Mathematical Principles of the Theory of
Wealth. And after Cournot but before Marshall, at least four
economists including Karl Rau, Jules Dupuit, Hans von Mangoldt, and
Fleeming Jenkin presented the diagram, often in quite elaborate and
sophisticated forms. Yet today we honor Marshall, not his forerunners,
by naming the diagram after him.

Why? Because it was Marshall who in his 1890 Principles of Economics
made the diagram sing and who put it on the map. It was his version
that caught the attention of the entire economics profession.
Stigler's Law again.