As correspondents for the Academy of Sciences, their missions basically consisted of providing exact data in order to draw up maps of North America. There was much imprecision about the location of the mouth of the Mississippi, and the French outposts in the region. The observations of Baron in Mobile in 1730 and in New Orleans in 1729 and 1731 proved the mapmaker Delisle right, who had disputed the findings given by Laval for Dauphin Island in 1720.
Laval, Voyage de la Louisane, 1728, title page BNF, Imprimés

Letter concerning the observations of Pierre Baron in Louisiane: "On the observation of a Lunar Eclipse on August 8, 1729, at New Orleans in Louisiana" Histoire et Mémoires de l’Académie Royale des Sciences, 1730, Histoire, p. 104-105 Bibliothèque de l'Observatoire de Paris-Meudon

Letter from Cassini concerning the observations of Pierre Baron in Louisiane: "Selection of various observations made in Louisiana by M. Baron, Royal Engineer. Compared with those made in Paris and Marseille. By M. Cassini." Histoire et Mémoires de l’Académie Royale des Sciences, 1731, Mémoires, p. 163-167. Bibliothèque de l'Observatoire de Paris-Meudon

Under the constraints of other, local needs, these scientists turned their hands with greater or lesser pleasure to other activities. Thus Laval gave his advice concerning the importation of European species: "This country will be good when it is under cultivation. There is, to my knowledge, no sugar, nor indigo, nor tobacco, nor vineyards, nor mulberry trees. But the Colony is only just starting. Neither those of the Spanish, nor ours, no matter how lively we are, will be built in a day". For his part, Baron worked as a engineer: "I work during the day with him [governor Périer] creating materials to be used for building, and the Night is given over to my astronomical observations". The traveling instruments used by Laval and Baron essentially consisted of a watch, a quadrant and a telescope. Laval had a quadrant that was approximately a meter in radius, a large telescope with a six-meter focal length and a "small" one of about two and a half meters, equipped with a micrometer. Baron installed his "observatory" on the terrace of the mansion of the governor of Louisiana. Thanks to this, he was able to observe a total eclipse of the moon and the emersion of the first of Jupiter's moons: for these achievements, he was complimented by Cassini.

There was a marked contrast between the ignorant indifference of the small Louisiana society and the esteem in which the papers written by Laval and Baron were held in France, where they were sometimes read at meetings of the Academy of Sciences. This gap is the best measure of the absence of remarkable individuals and lack of cultural life in Louisiana, at least up to the 1740s.