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Primary sourceBook1687

Principia Mathematica, Page 400 Scholium

Isaac Newton · 1687

A page from Book 2 of Newton's Principia showing his own reasoning on resistance and motion of orbiting bodies.

This page preserves Newton's own written reasoning from Book 2 of his Principia.

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Scanned page 400 of an old printed book in Latin, with a diagram of concentric circles labeled S, A, B, C, D, E, F showing orbits around a central sun, and dense columns of Latin text beside it. The page is cream-colored with a brown leather binding edge visible.
Isaac Newton, Philosophiae Naturalis Principia Mathematica, page 400, 1687. Wellcome Collection, London.

About this source

What it is

This is page 400 of Isaac Newton's Principia Mathematica (1687), containing a scholium (explanatory note) at the end of Section 9 of Book 2. It includes a diagram of concentric orbits and dense Latin text. It is held by the Wellcome Collection in London.

Why it matters

Book 2 of the Principia deals with motion through resisting mediums, part of Newton's effort to describe physical forces mathematically. This page shows his working method: diagram and argument side by side, revealing how carefully he reasoned through each problem.

Look closer

  • What does the diagram of circles around a central point seem to represent?
  • Why might Newton have placed a diagram directly beside the text instead of separately?
  • What does the density of Latin text suggest about who this book was written for?

This book is part of the curated material that grounds the AI version of Isaac Newton on Humy.ai — when students ask about related events, the AI can quote it and cite it.

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Title page of the 1687 first edition of Newton's Principia. Large capitals read PHILOSOPHIÆ NATURALIS PRINCIPIA MATHEMATICA, with author credit, Imprimatur by S. Pepys, dated Julii 5, 1686, and London printing by Josephi Streater, Anno MDCLXXXVII.Book

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Philosophiæ Naturalis Principia Mathematica

Isaac Newton · 1687

Title page with a page number marked [1] at top, reading PHILOSOPHIAE NATURALIS Principia MATHEMATICA, followed by the heading Definitiones and Def. I, with a Latin definition of quantity of matter in italic type. Faint bleed-through text from the reverse page is visible.Book

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Principia Mathematica, Page 1: Definitions

Isaac Newton · 1687

Black-and-white line engraving of an elderly man with long, wavy white hair seated in a dark armchair, wearing a dark coat, waistcoat, and white cravat, with his hands resting on his knee. A column appears at the right. Inscribed beneath: 'ISAACUS NEWTON EQ. AUR. ÆT. 83', with 'I. Vanderbank pinxit 1725' at lower left and 'Geo. Vertue Sculpsit 1726' at lower right.Painting

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Sir Isaac Newton, line engraving by Vertue, 1726

George Vertue · 1726

Engraved diagram on a cream page within a book, showing a curved comet path from Sol at left, with dated positions such as Nov. 25, Dec. 12, Jan. 5 and Mar. 5, labeled orbit lines and a sphere intersection line.Document

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Principia Mathematica, Fold-out Diagram

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Engraved portrait of Sir Isaac Newton, a man with long curled wig and dark robe, bust-length, against a shaded background. Caption below reads 'SIR ISAAC NEWTON' and publisher 'William Collins Glasgow & London'.Painting

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Sir Isaac Newton, stipple engraving by J. Scott after Kneller, 1702

J. Scott, after Sir Godfrey Kneller · 1702 (print made later)

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