Gilles presents an acceptable, to skeptics, scenario for the 1890's Airship wave(s) that we and Jose Caravaca have dealt with rather extensively in the past.
But looking at his and his team's presentation, we note that the opening salvo is couched in psychological terminology, leading us (and others) to believe that the explanation for the Airship sightings noted would be explained by psychology perhaps.
But Gilles et al. dispense with their premise and end up citing Venus as the cause of the California sightings, abetted by California newspapers and illustrations therein, with the only psychological element being a kind of watered down use of Freud's projection theory.
(I assume that the insert of the psychological terms, at the outset of Gilles' presentation, was a kind of faux imprimatur to give credence to what follows. Gilles, after all, is said to be a cognitive psychologist of some note in France.)
While links to material supporting the Venus hypothesis with which Gilles wishes to explain the California airship wave and those that followed are provided, they are a solipsistic farrago.
Venus, as an explanation for flying saucer and UFO sightings, and now the Airships seen in the 1890s decade, doesn't register as a methodological explanation for me and others who know from citations in THE NEW LAROUSSE ENCYCLOPEDIA OF MYTHOLOGY [Hamlyn, London, 1959, Pages 57, 58, 63, 76, 144, 311, 313, 323, 324, 431, 438, 442] and MYTHOLOGY: AN ILLUSTRATED ENCYCLOPEDIA, edited by Richard Cavendish [Rizzoli/Orbis, London, 1980, Pages 245, 248, 250, 251, 253] that Venus was perpetually seen as a planet or star by ancients and never once observed as a vehicle flying overhead and containing Gods or divinities despite, perhaps, the insinuations of the Ancient Astronaut theorists.
That Gilles and his cohorts, steeped in psychological maladies, present Venus as the observed Airships, exacerbated by newspaper accounts, which may have been bogus is interesting.
That would mean the observers were hallucinating or misperceiving in ways that could be etiologically explained, if one applied psychological methodologies to their observations. Gilles didn't do that and couldn't do that; unfortunately, no one has access to such observers (long dead), and one can't get into the mind of the newspaper reporters and editors (also long dead) who provided the stories (which many think were creations to accrue readers and newspaper sales).
Let me provide this experience:
When I lived in Florida in 1970-71, there was an old man, in his 90s, an artist, Fred Hoertz in an apartment below mine, who claimed he saw an airship when he was a child. While his wife said it was difficult for him to recall details of his sighting, in the 1890s, he did note that it seemed to him to be a flying mechanical device. This was a man with keen vision and painterly acumen. Did he think what he saw was the planet Venus? No. And I certainly didn't entertain any such idea, foreign to me even then, because this was an intelligent man who provided a brief statement of what he saw and thought it was.
If someone mistakes Venus for a UFO or the Airships that Gilles et al. proffer as an explanation for the 1890s Airship wave, that person should be noted for an hallucinatory episode, and studied from that perspective.
But too many persons saw the Airships under discussion, and Lucius Farish and Jerry Clark have provided exemplary reportage of those episodes, and we have, online here (which you can find via Google), a journalistic account of the sightings in a Midwestern magazine.
Nowhere does anyone presume to offer Venus as the cause of the sightings enumerated. The idea is silly on the face of it. And I'm surprised that Gilles and his cohorts have the temerity to present such an idiotic idea here or anywhere else.