Sources of "De la Terre à la Lune’s" lunar orbital calculations? Using them to establish a timeline for the narrative?

Skip to first unread message

Harpold, Terry Alan

May 10, 2024, 3:14:18 PMMay 10

Dear fellow Vernians,


I’m afraid that I’ve fallen into a rabbit hole with regard to De la Terre à la Lune (TL). I’m hoping that someone here can help drag me out and lead me to someone else who has already traveled this way and might show that my efforts have been either misguided or not entirely in vain.


I started by acting on a hunch that the calendar dates Verne gives in TL and related data regarding the Columbiad’s launch window, the timing of the Moon’s perigee, etc., must be significant because they are reported in precise terms. Verne’s narrator cannily avoids giving the actual years of the action of the novel anywhere, though the opening sentence of Autour de la Lune (AL) notes that the action of TL took place “pendant l’année 186–”.


Can we use TL’s indications of the timing of the perigee of the Moon’s orbit of the Earth to fix the timeline of the narrative more precisely?


In Walter James Miller’s annotated English translation of the novel (1978), he and David Woodruff, the technical consultant with whom Miller worked, pretty much give up on reconciling all of the numerical data in the novel, attributing the inconsistencies to: Verne’s having relied on multiple scientific sources, perhaps a few calculation errors, and a bit of artistic license. It’s not a significant issue, I think, to allow for slips of this kind. But if we turn to modern, online sources for lunar phases and lunar perigee and apogee, such as –



– the results looks promising, at least in support of Verne having paid attention to specific dates in TL.


If we assume that the advice given in the novel by “J.M. Belfast, Director of the Cambridge Observatory” (ch. iv) is correct about the timing of the following year’s perigee (December 4), then we might (?) date the launch  of the obus to as early as November 30 or December 1, 1868. In that year a lunar perigee does indeed fall on December 4. Which would suggest that Barbicane’s speech announcing the plan to build the Columbiad falls on the night of October 5, 1867. I think Miller and Woodruff may have looked into this but they don’t report much in the way of details. They observe in passing that December 1876 works for a December 4 perigee – actually, the perigee falls on December 3 of that year – but that is, they propose, too late in the overall timeline of the Voyage extraordinaires; I agree. And in any case that would contradict the observation in the opening line of AL. How Miller and Woodruff missed the 1868 perigee I don’t know.


Marie-Hélène Huet (L’Histoire des Voyages extraordinaires, 1974) proposes that the action of the novel unfolds in1865, but that seems too early to me. I know that now that the Civil War has ended the members of the Baltimore Gun Club are keen to keep blowing things up, but I think that a little downtime is required in order for them to become the restless, would-be exploseurs they are at the start of the novel. And the perigee data doesn’t add up: the December 1866 perigee falls on the 21st. William Butcher (“Les Dates de l’action des Voyages extraordinaires,” 1983) omits TL from consideration, probably because Huet had convincingly handled it (?). In Butcher’s Jules Verne inédit (2015), he reports (p. 141) that the TL manuscript includes a discussion among the members of the Gun Club about Abraham Lincoln having survived into a third or fourth presidential term (!), and a struck-through indication that the events of the novel are meant to take place in 1871. But this exchange in the MS did not make it into the published text. And the perigee data doesn’t work for that date either


Perhaps someone else has run these numbers and used them to calculate the year of the launch? Can anyone recommend an article or book that follows this idea through to its conclusions? Butcher observes (JV inédit) that Verne is still fiddling with data related to lunar phases, the perigee, the zenith, as late as the galley proofs for the in-18 and in-8 editions of the novel, and that Verne probably made numerous small modifications after consulting with one or more scientific colleagues (Garcet, de Jansson, de Bertrand, de Sainte-Claude)… is there much in the way of corroborating that?


Note this interesting aspect of the illustrations, the oddity that actually got me started on this journey. Apart from his diagram of the lunar phases, all of Henri de Montaut’s illustrations for TL that include the moon show it as a full moon. (The same is true of all but two of Bayard and de Neuville’s illustrations for AL.) If you run the numbers this doesn't work: if the perigee target date of December 4, 1868 is valid, Montaut’s depiction of Barbicane being carried through the streets of Baltimore on the shoulders of an enthusiastic crowd on the night of October 5, 1867 (ch. iii) should show a quarter moon in the sky; Montaut’s image shows a full or nearly full moon. The most likely explanation for this discrepancy is that the artists in both novels are taking their allotted license: the most poetically-invested version of the moon would seem to be the full moon, perhaps the new moon; quarter moons don't get as much respect. So, while Verne’s numbers and dates may be fairly reliable, the scientific apparatus of the novel has been in this regard decoupled from its illustrations.


As an aside, Jacques Crovisier’s article “À propos de quelques sources pour la Lune de Jules Verne” (Verniana 9), while not addressing the perigee data, is convincing on several other fronts, including Crovisier’s crediting Henri de Montaut’s south-up depiction of the moon’s surface to depictions in Garcet’s Cosmographie (1853), and in Magasin pittoresque (1833), and back to Cassini’s drawing of the moon from 1693. I tried tracing that lineage for a day or two on my own before remembering (!) Crovisier’s article, which came right to the point. My sincere thanks to him.


Keep watching the skies!




Terry Harpold

Associate Professor of English

Director, Imagining Climate Change


"Have you noticed my pink brains?

 You can see 'em work."

May 10, 2024, 7:47:49 PMMay 10

spot on. as you say. even in the published versions the information is rarely totally consistent and all the poor exegete can do is point out any clear contradictions. (some rarely venture into the thicket of details, contenting themselves to snipe from the sidelines.)


here are some of my idle jottings on the subject:


Quant aux dates internes du roman, dès les premières pages du manuscrit, Verne se met en quatre pour les rendre consistantes ; travail qu’il ajustera à plusieurs reprises avant la sortie de De la Terre à la Lune. L’intervalle prévu entre le lancement, le 1er juillet (ms xxvii 267), et l’alunissage, le 4 juillet (38), est à l’origine de trois jours. Dans les éditions in-18 du roman, en revanche, l’on prévoit un lancement le 1er décembre et une arrivée sur la Lune à minuit le 4 décembre. Dans Autour de la Lune, Verne indique que cette dernière date est erronée, sans avouer que l’erreur est la sienne : « leur arrivée à la surface du disque lunaire ne pouvait avoir lieu que le 5 décembre... et non le 4, ainsi que l’avaient annoncé quelques journaux mal informés » (chapitre préliminaire). Pour rectifier l’inconsistance, par mégarde il ajuste également le départ, écrivant « 30 novembre » à deux instances (i). Cette révision de la date de lancement implique la remise de cinq mois d’autres dates du roman, y compris sans doute les événements du Gun Club[1].


The info about Lincoln, by the way, was 1st reported in Olivier Dumas et Éric Weissenberg, « De la Terre à la Lune, une prévision ignorée et accomplie », Bulletin de la société Jules Verne (dorénavant : BSJV), no 155, 2005, p. 53-57, who omit, however, to consult the surviving proofs and the MS





You received this message because you are subscribed to the Google Groups "Jules Verne Forum" group.
To unsubscribe from this group and stop receiving emails from it, send an email to
To view this discussion on the web visit

[1] La date à laquelle la flotte de transport quitte New York, le « 3 décembre » dans le manuscrit (143), deviendra le « 3 mai » dans les éditions ; comme la fin du forage, le « 8 février » (144), y deviendra le « 8 juillet ». L’annonce fracassante de Barbicane au Gun Club ne se fera plus le « 3 mai » (Ms 13 et placards 9), mais le « 3 octobre » ; la dépêche de Michel Ardan, envoyée le « 30 avril » de l’année suivante (placards 160), le sera le « 30 septembre » ; la date prévue de l’observation du projectile, le « 2 août » (269), sera remplacée par le « 3 janvier » ; et sa date effective, du « 13 juillet » ou du « 11 juillet » (271), par le « 12 décembre ». Toutefois, il reste des inconsistances, que Verne essaiera encore de rectifier dans AL.

Harpold, Terry Alan

May 11, 2024, 10:11:47 AMMay 11

Thanks, Bill, these observations are very helpful. (I was unaware, by the way, of the Dumas & Weissenberg article. Will look into that.)


My intuition of the arc of both the composition of the novel and the changes Verne makes to the dates and deadlines – it’s more complex than this, but here’s a try at a simple version – is that Verne is adjusting things on the fly, probably in relation to ongoing conversations he’s having with Garcet, etc., as he learns more about the celestial mechanics involved, and to deal with historical matters beyond his control, such as the assassination of Lincoln. He makes some mistakes, he doesn’t always clean up the traces of the would-be fixes, he eventually runs out of time or interest in fixing everything.


(By the time we get to the third of the Baltimore Gun Club novels, Sans dessus dessous, 1889, Verne is so determined to get the physics of J.T. Maston’s colossal experiment in geoengineering right that he joins forces with Albert Badoureau to justify the outlandishness of the very idea. What’s the motive here? That the most fanciful of the misadventures of the Gun Club should appear the most scientifically credible?)


To land on the possible validity in TL of the December 4, 1868 perigee date as I have suggested here, isn’t to try to show that things aren’t really as messy overall as they are, so much as to propose that Verne may be closing in on a more scientifically-precise version of the story by the time we get to the in-8 edition. Even if, as I noted, the addition of the illustrations to the novel, which ignore the data on lunar phases in favor of aesthetics, throws things off with respect to the novel as an integral image-text. This, in fact, is not a small quibble or even an oversight of the illustrators; it’s deeply related to the tensions between the poetics of text and the poetics of image. (Heh, maybe I should write up something on this…?)


Terry Harpold

Associate Professor of English

Director, Imagining Climate Change


Terry Harpold has separate windings for thought, action, and speech.


From: <> on behalf of <>
Date: Friday, May 10, 2024 at 7:47
To: <>
Subject: RE: [JVF] Sources of "De la Terre à la Lune’s" lunar orbital calculations? Using them to establish a timeline for the narrative?

[External Email]

May 11, 2024, 7:27:24 PMMay 11



making it up as he goes along? definitely, especially the major innovations, like the weightlessness, the slingshot trajectory or the splashdown, even the escape velocity or the retrofusees. I even wonder whether, when he launched the projectile, perhaps under pressure from the publisher, he had any inkling of how to bring it back again.


little of this is in the scientific literature of the time so I suspect that we owe a huge debt of gratitude to Garcet.


Hope you can find time for an article on all this.




May 11, 2024, 10:21:09 PMMay 11
to Jules Verne Forum
I was not clear if Bill's account included the feuilletons: 

French unillustrated serialization in Journal des Débats politiques et litteraires:  
Part 1 (14 Sep 1865)-(14 Oct 1865). 26 chapters.
Part 2 (4 Nov 1869)-(8 Dec 1869).  24 chapters.

Sometimes the question comes down to how Google Translate presents the passage.

I could see the dates intended to be close to the publication of the serial story, much like Around the World in Eighty Days in Le Temps.

The subsequent book editions might use later dates to make them seem timely.

James D. Keeline

Tad Davis

May 12, 2024, 2:42:48 PMMay 12
Regarding the year when the launch takes place: when I narrated Ron Miller’s translation for Author’s Republic, I cheated. The opening of Around the Moon reads: 

During the course of the year 186–, the whole world was especially moved by a scientific experiment without precedent in the annals of science.

Nothing is uglier in audio than trying to say “during the course of the year eighteen-sixty-blank” or “eighteen-sixty-mmm.” Online discussions by narrators are rife with questions about how to read sentences like this without taking the listener out of the story. So with the translator’s permission I made a slight adjustment. 

Following the American Civil War, the whole world was especially moved by a scientific experiment without precedent in the annals of science.

Tad Davis

Reply all
Reply to author
0 new messages