It was plain to De Morgan that Nicollet was one of the few men alive in 1835 who could have woven the scientific fabric in which the hoax was disguised. It was also apparent to him that Nicollet, jealous of the popularity of Arago, might have had a motive for launching a satire, if not a hoax. And then there was Nicollet’s presence in America at the time of the moon story’s publication, Nicollet’s knowledge of English, and Nicollet’s poverty. The coincidences are interesting, if nothing more. * * * * * Let us see what the French said about Nicollet and the story that came to the _Sun_ from “a medical gentleman immediately from Scotland.” In a sketch of Nicollet printed in the “Biographie Universelle” (Michaud, Paris, 1884), the following appears: There has been attributed to him an article which appeared in the daily papers of France, and which, in the form of a letter dated from the United States, spoke of an improvement in the telescope invented by the learned astronomer Herschel, who was then at the Cape of Good Hope. It has been generally and with much probability attributed to Nicollet. With the aid of this admirable improvement Herschel was supposed to have succeeded in discovering on the surface of the moon live beings, buildings of various kinds, and a multitude of other interesting things. The description of these objects and the ingenious method employed by the English astronomer to attain his purpose was so detailed, and covered with a veneer of science so skilfully applied, that the general public was startled by the announcement of the discovery, of which North America hastened to send us the news. It has even been said that several astronomers and physicists of our country were taken in for a moment. That seems hardly probable to us. It was easy to perceive that it was a hoax written by a learned and mischievous person. The “Nouvelle Biographie Générale” (Paris, 1862), says of Nicollet: He is believed to be the author of the anonymous pamphlet which appeared in 1836 on the discoveries in the moon made by Herschel at the Cape of Good Hope. Cruel, consistent Locke, never to have written down the details of the conception and birth of the best invention that ever spoofed the world! He leaves history to wonder whether it be possible that, with one word added, the French biographer was right, and that it was “a hoax written by a learned and _a_ mischievous person.” Certain it is that Nicollet never wrote all of the moon story; certain, too, that Locke wrote much, if not all of it. The calculations of the angles of reflection might have been Nicollet’s, but the blue unicorn is the unicorn of Locke.