Variant Ageing Schemes of Elves

[Tar Elenion]

The information is drawn from Morgoth's Ring, Nature of Middle-earth and Vinyar Tengwar.
I have attempted to keep them in a date (earliest to latest) order. As most of them date from c. 1959, I attempted to arrange those in what seems to be a 'natural progression', though with the mass of them, I have probably jumbled something up...

MR, LQSII Laws and Customs
ca. 1958
In this, Elves physical growth is about the same as Men for the first 3 (sun) years. After the first 3 years, it seems to slow down to about 1/3 (if born at the same time time, when a Man reaches 'full stature', an Elf will resemble a (not more than) 7 year old, and will continue growing until 50 (presumably 'adulthood', as marriages start taking place 'soon after'), some might not be 'full grown' until 100.
In Aman, the years seem to refer to Valian/Tree-years (9.582 : 1), e.g. Finarfin marries 50 YT after he is born. It is not clear whether the pregnancy through age 3 is in SYs or YTs.

NoMe 1 III Of Time in Arda
not dated by CFH, presumably 1959
I The Quendi compared with Men
Tolkien writes that Elves are mature in body at about 20, have full physical vigour until about 60 (when the fea begins to dominate the hroa), and are at full and and wisdom at about 100 (in a process resembling Men).
He does not note what the ageing rate is, I presume because this is a set up text for the ageing texts that follow where he experiments with various rates (10, 12 , 50, 100, 144 to 1).

NoMe 1 IV Time-scales
c.1959
Ageing is "extremely slow". Elves are 'mature' at about 20 (24 for Elf-men, c. 18 for women). As with the Time in Arda text, Elves are in "full physical vigour" until about 60 and reach a state similar to Men of "high age and wisdom" at about 90-96.
This text has two different 'growth-rates':
1) a straight 144 : 1 (so an Elf-child reaches 'maturity' at about 20 = 2880 loa (Sun-years)
2) and a 12 loa (Sun-year) 'growth year' (related to the child being in the womb for 3/4 of that time). But it has also has a gestation of 3/4 of a yen = 108 loa (Sun-years).
I am not sure why the two different rates are in the text.
Tolkien notes that the ageing scheme will not work with the Silmarillion narrative, in particular Maeglin.

NoMe 1 IX Time-scales and “rates of growth”
c. 1959
In this text, the quendi all start with a 144 : 1 ageing rate, when the Eldar start on the Great March, a 'quickening' happens and the Avari ageing rate increases to 100 : 1.
The same happens to the Nandor when they forsake the March, and then the Sindar. Further, when the Doom of Mandos is spoken, it effects the Exiled Noldor as well.
It remains at 144 : 1 in Aman.
At a later point, Tolkien wrote in the margin against this: “no quickening” and “All this needs revision to duodecimal”.
In this text, Tolkien also notes that the Half-elven who chose to be accounted with the Elves have a 100 : 1. When he calculates Elrond's 'age' in Mortal terms, he does so from Elrond's birth, not factoring in that Elrond would have been at least 10 when the judgement regarding the Half-elven was made, would have remained less than 1 year old (in mortal terms) through the end of the First Age (despite having been in the War of Wrath), only '12' when he was Gil-galad's chief councillor and '17' when he led the relief army to Eregion and founded Imladris. And fell in love with '14' year old Celebrian.
He notes that Galadriel "at the exile" was "on the threshold of maturity" thus "about 20 × 144 = 2,880". In AAm, she would have been 1500-1362=138x9.582= ca. 1322 when Fingolfin's host made it to Beleriand.
He also calculates out the births and ages of Elrond's children (using the 100 : 1), compared to the marriage of Celebrian and Elrond.
He writes: “This must be erroneous” and tries adjusting the dates.
Later, in a marginal note, he writes "No. For child-growth (including time in the womb) to maturity was at rate 10 : 1. Gestation took 8 years...".

NoMe 1 X Difficulties in Chronology
c. 1959
In this text, Tolkien purposes several 'solutions' to the difficulties with the 144 and 100 to 1 growth/ageing rates.
In the first, he suggest a 144 : 1 in Aman, so Elves are adults at life-age 20 = 2880 Sun-years, but don't marry until 200 = 28,800 Sun-years.
I don't know what that actually 'solves'.
In the second, the Elves who did not go to Aman, and remained under the Sun quickened their maturity rate to 10 : 1, and thus were '20' in 200 Sun-years. They then lived at a 100 : 1 rate.
The third solution is as above, but with the addition of Elves born in Aman quickening their 'growth-rate' to 50 : 1 in Beleriand, until maturity.

MR, MT XI Aman
ca 1959
There is no quickening, Elves age at 144 : 1 and become 'mature' in about 3000 years.

NoMe, 1 XI Ageing of Elves
c. 1959
In Aman, Elves live at 144 : 1 with a "very long" youth, reaching 'maturity' at 20 = 2880 Sun-years.
In Middle-earth, It is 100 : 1, and Elves have a growth rate of 10 : 1 reaching maturity in 200 Sun-years.
Tolkien realizes this might be problematic with some of the (still) children from Aman not growing up fast enough in Beleriand and suggests a quickening to 50 : 1 for them.
Then he notes "This will not work".
He attempts to work through ageing of Finduilas and Idril (in 'contemporary draft material'), with doubling of 'growth-rates' during the march, and across the Ice, (so that they will be 'younger' than Turin and Tuor).
This text seems to have been written before the note about 'no quickening' and going to 'duodecimal'. The 'contemporary draft material' however, is 'duodecimal' and does not have a 'quickening'.

NoMe 1 V Youth of the Quendi
c. 1959
In this text, the growth-rate is 12 : 1, while life-rate is 144 : 1. Elf-men reach 'maturity' at 24 (288 Sun-years) and Elf-women at 18 or ("especially in Aman") 21 (i.e. 216 or 252 Sun-years). Pregnancy is 9 years. Note there is no 'quickening, and the text is 'duodecimal'.

NoMe 1 XII Concerning the Quendi in their mode of life and growth especially as Compared with Men
I. Youth and Ageing of the Quendi
c. 1959
This text gives the same numbers as the previous, but adds that Elves are in "full bodily vigour" ('youth’, vinyarë), for "about 72 coimendi or yéni after maturity".
That would be 96 'life-years' (10,656 Sun-years) for men and 90 (10,368 or 10,584) for women.

NoMe 1 VII March of the Quendi
c. 1959
This text also has a growth rate of 12 : 1.

NoMe 1 XVI Note on the Youth and Growth of the Quendi
c. 1959
Here Tolkien decides the differing calculations based on 12 : 1 and 144 : 1 are "cumbrous" and for the first generations of Elves after the awaking "quite unworkable". Pregnancy is 1 loa (Sun-year). Elves will grow at a 1 : 1 rate until 'mature' at 24 Sun-years. Males 'reach puberty' around 21 and females at 18.
"Vinimetta: ‘end of youth’: 96 = 24 löar + 72 coimendi = 24 + 10,368 = 10,392."

NoMe 3 XVI Concerning Galadriel & Celeborn
ca. 59
In this text, through various calculations, Tolkien indicates that a 12 :: 1 growth rate to 'maturity' (24), and then 144 : 1
e.g. "Amroth born S.A. 300. 2 in S.A. 588. In S.A. 1350 he was 29. In S.A. 1697 he was 31. In S.A. 3441 nearly 44 (43/117). In T.A. 1693 [he was] 11/109 older = 55/8"

NoMe 1 XVII Generational Schemes
c. 1959
Text 1
This text has a 1 Sun-year gestation, 1 : 1 growth-years, until 24, and then 144 : 1.
However, "End of Youth" is much shorter, coming at 60, which here is 24 growth-years + 36 life-years = 5208 Sun-years.

1 VI The Awaking of the Quendi
1960
This has two texts (A and B), and dates to the year following most of the prior texts.
After some of the previous texts had dropped the 'growth-rate' down to 1 : 1, this text increase it back up to 12 : 1, with 'maturity coming at 18 to 24 growth-years (between 216-288 Sun-years), followed by 144 : 1 for 76 to 82 life-years (10,944-11,808 Sun-years) with "prime" at 100 (11,160-12,906).
Tolkien, also considers slowing the 'growth-rate' in Aman to 36, 72, "or even" 144 : 1.

NoMe 1 VII Elvish Ages & Númenórean
15/Aug/1965
5 years later, Tolkien states that:
"Elves’ ages must be counted in two different stages: growth-years (GY) and life-years (LY)."
In Middle-earth the growth-years are 3 : 1 and life-years are 144 : 1. He does not state what the 'growth-rate' is in Aman. I think he implies that the 'life-years' are still 144 : 1.
Elves are "in womb 1 GY", reach ""full speech" and intelligence in 2 GY", and ""full growth" of body in 24 GY".
This is followed by "48 LY of youth" and "48 LY of "full age" or "steadfast body"".
This would be "maturity" at 24 (72 Sun-years), ""youth"" ending at 72 ( 72+6912=6984 Sun-years) and ""old age"" comes at 120 (13896 Sun-years). Then Elves start "(very slow)" to 'fade' ( the fea slowly 'consumes' the hroa).

NoMe 3 XI Lives of the Númenóreans
c. 1965
V.T 47 Eldarin Hands, Fingers and Numerals
c. 1968
NoMe 1 XIX Elvish life-cycles
c. 1969

Al three of these imply a 1 to 1 growth-rate until 'mature', with some form of 'Elf-children grow about as swift as Men to physical (and even mental in 1 XIX) maturity'.