Tuesday, December 22, 2009

How tall was Isaac Newton? 5 feet 6 inches, perhaps shorter (with a new addition regarding Isaac Newton himself on height)

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Milo Keynes, M.D., (born 1924, died February 18, 2009) worked in the Anatomy Department at Cambridge University, England (where Newton himself spent 42 years). Dr. Keynes believed that Newton was five feet six inches tall. I rely heavily on his research and hereby credit him. I have added a few quotations from other sources that I have found, cited below, which corroborate Dr. Keynes views.

Dr. Keynes was the nephew of the famed English economist John Maynard Keynes and was also the great-grandson of Charles Darwin. He became fascinated with Sir Isaac Newton as a boy when a huge cache of Newton’s original handwritten papers were sent to him for safe keeping under his bed in northern England to protect them from possible destruction during the Axis bombing of London in World War II.

See: Keynes, Milo, The Personality of Isaac Newton, Keynes Notes Rec R Soc, 49 (1), footnote at page 3

Website: http://rsnr.royalsocietypublishing.org/cgi/reprint/49/1/1
footnote at page 3

Dr. Keynes went to great lengths to establish Newton’s true height. As a medical doctor and one who was expert in anatomy, we should trust Dr. Keynes assessment.

As Dr. Keynes has written:

“Sir Isaac Newton told John Conduitt, husband of his half-niece, Catherine Barton, that, when he was born on Christmas Day 1642, ‘he was so little they could put him into a quart pot & so weakly that he was forced to have a bolster all round his neck to keep it on his shoulders’, and thought unlikely to survive. He was undoubtedly a diminutive neonate, with a low birth weight more likely to have been due to poor, or improper, nourishment while in utero than due to premature birth by more than a few days and still have survived in the seventeenth century. He was short of stature at five feet six inches tall (the same as Beethoven and Napoleon), and the statue of him in the Chapel of Trinity College, Cambridge gives him a small head, which Roubiliac had sculpted using his death mask for size.”

Source: http://www.galtoninstitute.org.uk/Newsletters/GINL0103/

Dr. M. Keynes has stated several times that Newton stood five feet six inches.     See Keynes, Milo “The Iconography of Sir Isaac Newton to 1800” Boydell Press (February 1, 2005) ISBN-10: 1843831333 at pages 31 and 51.

See also, Keynes, Milo, The Personality of Isaac Newton, Keynes Notes Rec R Soc, 49 (1), at page 6
Website: http://rsnr.royalsocietypublishing.org/cgi/reprint/49/1/1

The Eyewitness Accounts

Under the law, direct evidence is from eyewitness accounts. These combined with the circumstantial evidence, infra, conclusively prove Newton was of short stature.

Among the eyewitnesses who knew Newton well are the following quotations:

1. John Conduitt’s Memoir of Isaac Newton. John Conduitt was married to Newton’s half-niece Catherine Newton. He saw Newton regularly and wrote a description of his appearance in which he originally wrote that Newton was of “short” stature and then changed “short” to the more charitable description of “middle” stature. It should be noted that a five feet six inches would be about middle or medium height for a man living in the 1600’s.

The full quotation from the original manuscript appears below, taken from the Newton Project online (citation noted below quote):

“He was never married,\./ sober & \He was very/ temperate in his diet but never observed any regimen he was blessed with a very happy & vigorous constitution, he was short of a \middle/ stature & in \plump/ \in/ his later years inclining to be fat, had a very \lively &/ peircing eye & a countenan \comely \&/ gracious/ aspect <13v> had a fine head of hair \as white as silver some of \without any baldness /&\// he would often appear from under his wig \& when his periwig was off was a venerable sight/, & to his last illness had the bloom & colour of a young man & never used spectacles nor lost but one \any more than one/ tooth to the day of his death”

Source: Keynes Ms. 129 (A), King's College Library, Cambridge 

Website:  http://www.newtonproject.sussex.ac.uk/texts/viewtext.php?id=THEM00145&mode=diplomatic

That Conduitt was being diplomatic in describing Newton as “middle stature” and not, as he originally wrote, “short” can be safely inferred by his substituting the word “plump” instead of his original and more blunt phrase “inclining to be fat.” 

Hence, instead of saying Newton was “short and inclining to be fat” –as Conduitt originally wrote and which would be almost rude--we get the far more euphemistic description that Newton was of “middle stature” and “plump.” The word “plump” is almost cutesy and, obviously, this is a less harsh and more indirect way of describing Sir Isaac Newton’s weight. The inference, however, is that Conduitt was right the first time and Newton was in reality “short and fat.”

2. William Stuckley, M.D. knew Newton personally, and was a fellow member of the Royal Society. In 1752 he wrote an account of the late Sir Isaac Newton and gave this description (I found this from the Newton Project on line):

“Wm STUKELEY, M.D., F.R.S. 1752 

Being an \some/ account \of his family; &/ chiefly of the junior part of his life.
Sr Isaac was gray headed when under 40; owing, perhaps, to the infinite expence of spirits from <61> severe studys; yet he had great strength of nre, & a good constitution. tho' not tall in stature, yet strong, sinewy, & well made. ”


From the above passage it is frankly stated that Newton was “not tall.” We can infer from the almost apologetic tone of the passage that Newton was likely on the short side. Thus, the phrase “not tall in stature” is introduced by the word “tho’” [though] and quickly followed by the phrase “yet strong, sinewy, & well made” as if to almost apologize for the short stature of Newton and point out that he was well proportioned despite lack of height. 

Stukeley gives another passage, which I also found on the Newton Project on line, describing Newton’s voice:

“his voice was of a deep tone, but pleasant enough, having a large chest, for one of his stature.”



The phrase, “having a large chest, for one of his stature” alludes to Newton being of small stature since it would make little sense to say he had a large chest for a large man. One would naturally expect a large man to have a large chest. Yet it would be notable for a short man to have a large chest. Hence, the phrase, “having a large chest, for one of his stature” should safely be interpreted as Newton having a large chest for a short man.

 Stukeley was a medical doctor and had a trained eye sizing up physiques. For him to say Newton was “not tall in stature” it follows that he must be credited with making an accurate, trained medical observation. 

Further, to be “not tall” in the 1600’s would mean that by today’s standards Newton would probably be a short man perhaps even shorter than five feet six inches. Both Stukeley and Conduitt, it has been conceded by Newton scholars, wrote adulatory biographies of Newton. Stukeley does not say Newton was of medium height but instead says he was “not tall.” A person of medium height would not be described as “not tall” but simply as being of average height. Hence, “not tall” could be taken as a tactful, diplomatic way of saying “short.”

3. Thomas Hearne (1678-1735) was an Oxford scholar and antiquarian renowned for his deep scholarship. Hearne knew Newton. This is his description of Newton: 

“ . . .Sir Isaac was a man of no very promising aspect. He was a short, well-set man. He was full of thought, and spoke very little in company so that his conversation was not agreeable. When he rode in his Coach, one arm would be out of the Coach on one side, and the other on the other.”

Source: David Brewster in Memoirs of the Life, Writings, and Discoveries of Sir Isaac Newton, page 414

See also: 
Hearne, Thomas 1727 Reliquiae Hearnianae, ed. Bliss, April 4, vol. II, p.311

See also: http://books.google.com/booksid=1UAFAAAAYAAJ&pg=PA712&lpg=PA712&dq=,+and+spoke+very+little+in+company+so+that+his+conversation+was+not+agreeable.&source=bl&ots=UhxeXWuRal&sig=5wk8FM_Hi3tJdVY8fsRtiGpjngM&hl=en&ei=uY4PSqqJCpXktAPT6fmRAw&sa=X&oi=book_result&ct=result&resnum=1#PPA712,M1

See also: A Biographical Sketch of Sir Isaac Newton by E. F. King, page 65 at: 

Hearne bluntly states that Newton was “short” and “well-set.” For a man to be considered short in the 1600’s, Newton must have been well below modern average height for a man. Moreover, Hearne specifies that “Sir Isaac was a man of no promising aspect.” From this eyewitness observation one can conclude that there was nothing conspicuous about Newton. It follows that Newton was—as Hearne clearly states—a short man who would not stand out in a crowd. 

Hearne’s eyewitness account that Newton was “short”, combined with the eyewitness accounts of Conduitt (who originally wrote that Newton was “short” and changed it to “middle stature”—meaning “middle stature” for a man in the 1600’s which would be small by today’s standards) and Dr. Stukeley who wrote Newton was “not tall” and had a “large chest, for one of his stature” show that Newton was on the short side based on direct, eyewitness evidence.

4. Dr. Milo Keynes also cites the portrait of Sir Isaac Newton made by George Vertue (1684-1756) in 1726, after the portrait of John Vanderbank, 1725, at the Royal Society, for the engraved frontispiece of the third edition of the Principia in 1726. Dr. Keynes states that portrait shows that Newton was a short man, and had become plump by the age of 83. Since Newton died in 1727, and since this was the engraving of him on the third edition of the Principia was published while he was alive in 1726, it is likely that Newton himself saw this engraving by Vertue and approved of it. Newton was known for his attention to detail as well as micromanaging matters when he was at the Mint so it seems unlikely that Newton would not have noticed this engraving which was the first time a portrait of him appeared on an edition of the Principia. It can be thus inferred that Newton approved of this depiction of himself, a tacit admission that he was short.  

Source: Keynes, Milo “The Personality of Isaac Newton” at pages 6 and 7 http://rsnr.royalsocietypublishing.org/cgi/reprint/49/1/1

5.  ADDITION TO POST ON JUNE 4, 2013 :  Before we leave the Eye Witness accounts on height, it is interesting to see what Isaac Newton himself wrote on human height.  The following quotation is taken from the Newton Project at  http://www.newtonproject.sussex.ac.uk/view/texts/normalized/THEM00276

Newton is trying to calculate the dimensions of an ancient building, and concludes that the "ordinary stature of men" was about the same 3,000 years ago as it was in Newton's time, namely 5 feet six inches, which is exactly the estimate I have given for Newton's own height.

Here are the quotations from Newton himself:

"The measures of Feet and Cubits now far exceed the proportion of human members; and yet Mr. Greaves shews from the Ægyptian monuments, that the human stature was the same above 3000 years ago, as it is now. . . .
The stature of the human body, according to the Talmudists (f)[6], contains about 3 Cubits from the feet to the head; and if the feet be raised, and the arms be lifted up, it will add one Cubit more, and contain 4 Cubits. Now the ordinary stature of men, when they are bare-foot, is greater than 5 Roman Feet, and less than 6 Roman Feet, and may be best fix'd at 5 Feet and an half." [underlining added]

So, Newton himself believed that the ordinary stature of men is "5 feet and an half" or  5 feet six inches !  
Since Newton has been described by eye-witnesses as being of "middle" or "middling" height, it seems sensible that this height was around what Newton himself considered ordinary, or  5 feet six inches. Interestingly, Newton concludes "ordinary" height to be his own height.

Circumstantial evidence:

1. From Conduitt’s memoir of Newton, op cit, we have the following first hand account from Newton himself regarding his birth size as told to John Conduitt:

“ Sr I. N. told me he had often heard from his mother that when he was born he |was| was so little they could have put him into a quart pot, |not above half the bigness much below very much less than \below/ the usual size of children| & so unlikely to live that two women who were sent to My lady Packenham at North Witham \a neighbour/ for something <16> for him sate down on a stile by the way, & said {sic} \saying/ the one to the other the one to the other they need not make haste, for the child would certainly be dead before they could get back. He for some time {wore a} bolster round his neck to keep \support/ his head upon his shoulders –”

Source: http://www.newtonproject.sussex.ac.uk/texts/

Dr. Milo Keynes concludes that Newton was undoubtedly a diminutive neonate, with a low birth weight. While it is of course possible that a tiny baby may grow up to be a large man, the stronger likelihood would be for a neonate to grow up to be on the short side. 
See: http://www.galtoninstitute.org.uk/Newsletters/GINL0103/

Conduitt also wrote, 

“he was very much below the usual size of children”

Source: John Conduitt, Keynes-Newton, MS. 10, King’s College, Cambridge.

See also: Keynes, Milo “The Personality of Isaac Newton” op cit. at page 5.

Not only does Conduitt say Newton was “below the usual size of children” but he prefaces it with the remark that he was “very much” below usual height as a child. Not only below average but “very much” below average. Again, the likelihood is that a small child would not grow to be tall.

2. The death mask of Newton, still extant, reveals that he had a small head. Years after Newton’s death, the expert sculptor Roubiliac carved a statue of Newton for Trinity College, Cambridge University using the death mask as a model for the head. Dr. Keynes believed that the statue is a bit idealized and probably not life-sized but it does show Newton’s head as being small. Indeed, the statute, carved years after Newton died shows the head as being in much smaller proportion to the body suggesting that the body of Newton was idealized but the head was more accurately carved since it was done from the actual death mask of Newton. The death mask is direct evidence of the probable size of his head. While it is possible that someone with a small head could have a large body it is more probable that a small head would belong to a small body.

Source: Keynes, Milo “The Personality of Isaac Newton” op cit. at page 6.


The Royal Society has kept what is reputed to be a walking stick used by Newton. Dr. Milo Keynes tested the stick. Dr. Keynes was six feet tall and found the walking stick a good six inches too short for him, further evidence in Dr. Keynes’ opinion that Newton was five feet six inches tall. Again, Dr. Keynes was an M.D. and trained anatomist; his medical opinion should carry some weight. 

Source: Keynes, Milo “The Personality of Isaac Newton” op cit. at page 6.

3. Eloge du Chevalier Newton by Bernard Le Bovier de Fontenelle. 
The Life of Sir Isaac Newton. With an Account of his Writings (London: 1728):

“He was of a middling Stature, and very lean, his Eye quick and piercing, his Face agreeable and venerable at the same Time, especially when he threw off his Peruke, and shew'd a large Head of Hair, which was perfectly white; he never made use of Spectacles, nor lost but one Tooth in his whole <28> Life. His great Name will justify the mentioning these minute Circumstances.”


Source --See:

This is from the original manuscript of “Life of Newton.”   The published edition differs a bit, as noted infra.  

Note that “Life of Newton” was the first biography of Newton and was published just one year after his death. It states Newton was of “a middling Stature”; again, “middling” in the 1600’s would most likely be considered short by today’s standards. 

I am unsure if Fontenelle personally met Newton so this cannot be considered an eyewitness description. Nevertheless, since this biography was published so soon after Newton’s death there would still have been plenty of people alive who knew Newton personally and who could have questioned this description yet based on the extant sources no one apparently did so.

 Indeed, Conduitt uses a similar description of Newton’s height, “middle stature.” Perhaps it was reading this first biography of Newton that compelled Conduitt to change his description of Newton from “short” to “middle” echoing the word “middling” used by Fontenelle. Note that the Newton Project opines of Fontenelle’s biography, “This first biography largely shares the adulatory tone of the accounts by John Conduitt and William Stukeley” ; hence, one can infer that since the biography was adulatory, “middling stature” was a polite way of referring to Newton being on the small side.

 Note also that in the finished edition, the statement that Newton was “lean” has been changed. 

Also, later translators have changed the phrase “middling stature” to “mean stature” as in the following translation:  

“He was of a mean Stature, and a little inclin'd to fulness in his later years, of a quick and piercing eye, with a countenance at the same time venerable and engaging, especially when he would throw off his Perruque, and shew his silver Hairs, which hung down in large locks upon his shoulders. He never made use of spectacles, nor lost any more than one single Tooth during his whole life. His name will justify our descending to these minute particulars.”

See transcription by David R. Wilkins (2002) at :



There you have it: Three eyewitness accounts describing Newton. None of the eyewitnesses describe him as tall. On the contrary, he is described by Stukeley as “not tall”; by Conduitt initially as “short” (in his original manuscript description, later amended to “middle stature” –which middle stature for a man in the 1600’s would mean shorter than an average sized man today) and by Thomas Hearne who bluntly described Newton as “short”. 

The circumstantial evidence is equally powerful: The engraved portrait that appeared on the 1726 third edition of Principia, published while Newton was still alive and likely seen by Newton, shows Newton to be a short man according to medical doctor and anatomist Milo Keynes. The death mask reveals a probable small head. Newton himself told John Conduitt that he was a very tiny baby, and that he was very much smaller than other children suggesting that he would grow up on the short side. Fonetelle’s second-hand description of him is that he was reportedly of middling height for a man in the 1600’s. The walking stick attributed to belonging to Newton is for a short man according to Dr. Keynes. 

Newton himself wrote that 5 feet 6 inches was the ordinary height for a man which, more than coincidentally, was Newton's own height.  Newton was probably five feet six inches tall and perhaps shorter.