“O Osiris! The inundation is coming; abundance surges in. The flood-season is coming, arising from the torrent issuing from Osiris, O King, may Heaven give birth to thee as Orion!”
– Pyramid Texts
I have argued before that the images on f80v relate to the inundation of the Nile on the one hand, and certain constellations on the other. Since then, I have come to understand better why these specific constellations were chosen. This should enhance the strength of the analysis, since each part of the story confirms the other.
Life in ancient Egypt, and up until fairly recently, was dictated by the cycle of the Nile. Around the same time each year the river would flood, fertilizing the fields around it and allowing human life to continue in the desert. This is why Egyptians were obsessed with concepts like fertility and the cycle of death and rebirth, which permeated every corner of their art, custom, lore and religion, arguably more so than in other cultures. This was still very much the case in later periods, as exemplified by the Isis-Osiris cycle which gained an immense popularity under Greco-Roman rule. And dependency on the annual inundation of the Nile remained a constant until the construction in the Aswan dam in the 1960’s.
It is no wonder then that the Egyptian calendar reflected the pace of life dictated by the river:
On the regular behaviour of the Nile rested the prosperity, the very continuity, of the land. The three seasons of the Egyptian year were even named after the land conditions produced by the river: akhet, the “inundation”; peret, the season when the land emerged from the flood; and shomu, the time when water was short. When the Nile behaved as expected, which most commonly was the case, life went on as normal; when the flood failed or was excessive, disaster followed. (Britannica)
Akhet was the season of the inundation, which lasted about four months. “The first signs of the inundation were seen at Swentet (Aswan) by the end of June, reaching its swelling to its fullest at Cairo by September. The flood would then decrease in size around two weeks later, leaving behind a deposit of rich, black silt.” 
To irrigate fields further up the bank, canals and other systems were in place. Often a shaduf was used to lift the water and pour it up to a higher level. Here’s some nice old footage that shows how traditional farmers were still using these ancient methods: video youtube.
Why is all this important? Well, the Egyptian seasons weren’t just some weird cultural or religious convention. If you wanted to live in Egypt and survive, or even just deal with Egyptians, it was crucial to understand the rhythm of life in these lands. In other words, information about the cycle of the Nile was useful to non-Egyptians, also in the 15th century. At least for those who wished to venture beyond the borders of their homelands.
But why does f80v relate to the inundation of the Nile? Well, in several ways, and each confirms the other. To explain this, it is the best to focus on the middle and bottom of the page, where water is present in the images.
As you can see, the images are arranged around the margins, leaving room for large blocks of text in the middle. The fact that the image is forced into the square shape of the page has the consequence that this cannot be an exact diagram of the Nile. It is more of an abstract representation.
Now, the next step: let’s get rid of those pesky nymphs and see what’s left. In order to do this, I traced all the lines of the water-related elements. Basically I left the human figures out. I also compressed the middle part, bringing the left and right margin closer together in order to make the image more blog-friendly. The only effect of this is that the river down below has become shorter than it was originally.
The diagram starts top right. First (1), we see the water running down from the higher areas and mountains in the south. There is a rapid river passing what looks like rugged terrain. In the bottom, it enters the wide, blue river that runs horizontally across the page. It clearly goes beyond its bounds (2), irrigating the surrounding fields. Finally, I think (3) might represent pipes, canals, shaduf and/or other systems of irrigation. 
What about the nymphs, then?
I have often argued that the human figures in this section (q13a) allude to the Greek constellations.  There are parallels in the Greco-Roman pictoral tradition, and clues in the writings of the likes of Eudoxus, Aratus and Hyginus.
Since I have written about this before (see my paper on this folio here), I will just briefly go over the most important figures again here. The figures we will focus on are those closest to the river:
In all of these folios there some aspects of the drawing which very often point the viewer towards the intended constellation. Presumably this was known to the original audience of these images, whenever they first originated, possibly accompanied by a text.
- The base upon which the figure stands has been given a shape relevant to the constellation.
- The nymphs are like actors, using their stance to play the constellation.
- Especially the arms are telling.
Armed with this knowledge, we’ll quickly go over these five constellations in order.
1: Orion, the striding giant
Orion is one of the few constellations already given a proper name by Homer. Despite this ancient origin, the myths surrounding this figure and the constellation are often vague. There is no standard iconography for the mythological figure. What we know for sure is that Orion was a great hunter wielding a club (also a sword and/or scabbard in later times). But above all, he was a giant capable of treading the ocean floor and still keep his head above the water.
The same characteristic returns in descriptions of the constellation itself. For example, Manilius writes that “Orion may be seen stretching his arms over a vast expanse of sky and rising to the stars with no less huge a stride.” Basically everything about Orion is wide and huge. This is brilliantly reflected in the corresponding nymph, which has about the hugest stride in the manuscript, and massively long arms like a chimpanzee. Additionally, her whole body is much bigger than that of other nymphs on the same page.
I believe the base on which Orion stands is supposed to bring to mind his weapon, which Homer describes as “a mace of bronze, never to be broken”. Alternatively, and perhaps more likely, it is shaped like the scabbard which hangs from the constellation’s famous belt.
A final argument, is that the little “mountain river”, which represents the constellation Eridanus, starts at the bottom of this figure. For example Eratosthenes writes: “The river has its source at the left foot of Orion.”
2: Cetus, the sea monster
The river constellation, Eridanus, flows past the constellation of Cetus, a terrible sea monster. And indeed, the base of these nymphs brings to mind Cetus’ typical coiled tail.
The Voynich has it right even down to the split end of the tail, compared here to that on the Farnese Atlas and the Mainz Globe, two of our most authentic ancient sources for constellation imagery.
The nymphs provide an additional nod to the most relevant constellation lore: Cetus was slain by the hero Perseus, who carried in his hand the severed head of Medusa.  See fpr example the following Roman mosaic found at Zeugma, modern day Turkey.
3: Lepus, the Hare
We can be swift here: the arms are the ears.
4: Canis Major and Sirius, the Dog star
Given her location compared to the other nymphs, one can only expect the next nymph to represent the constellation (and star) so important for the inundation: the Dog and Sirius. But the figure is relatively plain at first sight, she doesn’t give us much to work with. Luckily we have some tools at our disposal.
The base: well, she stands in a literal inundation, the river becoming wider around her…
The arms: if the arms of her companion are the ears of a hare, well, then these would make some decent dog ears. Additionally, I shall quote JK Petersen on this nymphs breasts: “I’ve always thought of this nymph as having “eyeball” style breasts… drawn with circles instead of bumps“. I agree: if the arms are the ears then the breasts are the eyes.. Furthermore, I can’t shake the impression that red paint has been applied to them, though this is hard to see on the scans.
If this is the case, then it only strengthens the analysis, since for example Manilius called Canis the dog with the blazing face, referring to the bright star Sirius within the constellation.
5: Hydra, Corvus and Crater
These three constellations are generally treated as a trio, and the same is true in their Voynich versions. Crater (a cup) and Corvus (a crow or raven) are standing on Hydra (a water snake). The following image should suffice to show that the nymphs assume the same general positions:
But there is more: keep in mind that the nymphs use their arms to assume the shape of their constellations. Crater, the standing nymph with the puffy face on the left, is holding her visible arm like a cup’s handle.
And Corvus (crow/raven) is holding her arm slightly bent on her back, like a bird’s folded wing.
Finally, the nymph portraying the Water Serpent is lying horizontally, a very exceptional orientation for Voynich figures, but all too appropriate for the long serpent. Her arm appears strangely wavy and serpentine as well.
This concludes the figures that are most strikingly associated with the water, and their corresponding constellations. A final factor connecting them all is the river, which appropriately starts at Orion’s legs and passes by Cetus, Lepus and Canis.
But what is the relation between the inundation of the Nile and these constellations?
Sirius (nymph #4 in the overview) was important in Egypt because it heralded the arrival of the flood. The star got its own goddess, Sopdet. In the Greco-Roman period, Sopdet remained an important figure associated with the flood and fertility and she was syncretized with other goddesses like Isis and Demeter.
Also the constellations close to Syrius were connected to the Nile in Egyptian, Greek and Roman lore. The giant Orion (nymph #1) was already associated with Osiris and the flood in the Pyramid Texts, an association which arguably became even stronger in Greco-Roman times.
Similarly the southern river constellation Eridanus, which originates at Orion’s foot, was naturally associated with the Nile.
Lepus (nymph #3), the swift hare, is a small constellation often seen as belonging to Orion – the hunter and his prey. In Egypt, too, these stars were associated with the much more prominent Orion/Osiris. 
Cetus (nymph #4) was a sea monster sent to southern Egypt to punish the local rulers.
Hydra (nymp #5), much like Sirius, coincided with the start of the flood. Theon of Alexandria knew that the Egyptians called it Hi or Hiu, which meant “to inundate”, effectively naming these stars after the yearly event that started at their rising. 
So all of these constellations relate to Egypt in some way, and most of them are specifically linked to the inundation of the Nile, both in the season when they were visible in the sky as in their lore, the latter taking the upper hand in later periods.
But wait… there’s more.
A while ago I noticed that the famous manuscript Vat.Gr. 1291 had finally been digitized. A certain image in this manuscript has been known among Voynich researchers for a long time, and with good reasons . However, my attention was drawn to a different illustration, of a so-called summer hemisphere. There are some other, later manuscripts with similar hemispheres. Elly Dekker calls these the “Ivy Leaf group” because they all contain a mysterious, otherwise unknown constellation in the shape of an ivy leaf.
On the source of these images, she wites: “One can say, albeit with some hesitation, that the archetype(s) of this group of hemispheres emerged in the centuries after 128 BC, but not much later than AD 300.”
But even more surprisingly, there is another manuscript of this group, made in the 14th century, which is apparently even more true to the ancient originals . Dekker writes:
Despite being the most recent example, the set of hemispheres H10 in the ﬁteenth—century MS Vat. gr. 1087 is the best representative of the ivy leaf group (Fig. 3.1o).The other Byzantine set of hemispheres H11 (MS gr. 1291) is in many respects inferior to H10.
This is extremely important for my analysis, since it shows that relatively late medieval manuscripts can reach past intermediate copies and deliver imagery most authentic to their ancient sources.
Now, to get to the point. A summer hemisphere basically shows that half of the celestial globe which would be most prominently visible in summer. In the image below, I took the summer hemisphere from the very authentic MS Vat. gr. 1087 and circled in blue the southern section, the part below the Zodiac circle . I started at Orion and numbered the constellations as they appear in the Voynich f80v.
We see the giant Orion (1) with the river starting near his foot. The monstrous Cetus (2) with his coiled tail. The swift Hare (3) with its long ears. And right in the centre on the summer solstice, the Dog (4), with the rays of Sirius beaming around its face like a second Sun. And the long Hydra (5) with Corvus and Crater. And finally, note how the river Eridanus connects Orion, Cetus and Lepus.
So that’s it. A group of constellations which were visible in the south during the summer months, the place and time of the annual flood. It is no wonder, then, that these constellations became associated with Egypt and the inundation of the Nile. And it is no wonder that they are grouped on this folio.
 As a side note: if the river on the right is the High southern Nile, and the river in the bottom is the Low northern Nile, then might the blue circles represent lakes or something similar? See for example this map from an 11th century Arab manuscript, an illustration of Ptolemy’s description of the Nile. South is up here, as was the custom. The Nile originates in the mythical “Mountains of the Moon” and then passes through several lakes before ending up in the Mediterranean.
Confronted with this map, a solution for the base of the final figure emerges: if the other end of the line is the high origin of the Nile, then this may be the mouth (delta).
In the Voynich “Delta” we count seven lines, i.e. seven mouths of the river, which is in line with authors like Ovid:
“… to have lead his victorious ships up the seven-mouthed flood of the papyrus-bearing Nile“.
 I am indebted to Diane O’Donovan, who argued before that the human figures in this section, and indeed in other sections, represent stars, and that the imagery originated in a Hellenistic context. My views differ from hers, however, in that I believe these images are informed by the Greek (or Greco-Egyptian) tradition of descriptive or even poetical astronomy. Additionally, at least the nymphs in quire 13a refer to a set of “standard” Greco-Roman constellations rather than individual stars. Of course there are some instances where a star is much more important than its constellation, as is obviously the case for Sirus.
 Thanks to JK Petersen, who pointed out the reference to Perseus in this figure, which I had not yet noticed.
 Hyginus writes on Eridanus: “Some call this the Nile, though many call it Ocean. Those who advocate the Nile point out that it is correctly so called on account of the great length and usefulness of that River, and especially because below the sign is a certain star, shining more brightly than the rest, called Canopus. Canopus is an island washed by the river Nile.”
 See http://www.eastbayastro.org/articles/lore/lepus.htm
“These stars [of Lepus] below the great hunter’s feet have been known as the Boat of Osiris. The four major stars of Lepus form an easily recognizable trapezoid.”
 See for example Gerald Massey: https://books.google.be/books?id=IDCju2TrweMC&pg=PA347&lpg=PA347#v=onepage&q&f=false
 See http://www.voynich.nu/extra/vatg1291.html
 On the way this copy was established, Fabio Guidetti writes: “solo alla volontà di recupero antiquario di Niceforo Gregora si deve infatti la fortunata sopravvivenza delle illustrazioni del codice Vat. gr. 1087″
(L’apparato iconograﬁco del codice Vat. gr. 1087. Per la ricostruzione dell’edizione tardoantica del corpus arateo.)
 By convention, celestial spheres and hemispheres were mirrored, as if one was viewing from outside the sphere. In order to get a “normal” view, as seen from the ground, I had to mirror the image.