How to Peruse a Book

Long after he had earned tenure and had established his place at the university, our historian of science continued consuming books as he had as an undergraduate. In the summer of ’73 he took with him on vacation his copy of C. Truesdell’s The Rational Mechanics of Flexible or Elastic Bodies, an introduction to Leonhard Euler’s Opera omnia.

Truesdell on Euler—Light reading for a summer vacation.
Truesdell on Euler—Light reading for a summer vacation.

I can’t say I would bring The Rational Mechanics of Flexible or Elastic Bodies to my summer cabin, but I respect his dedication: “First perusal, completed, The Cabin, Logan Canyon, June 30, 1973.”

Perusing Euler while lounging at the cabin.
Perusing Euler while lounging at the cabin.

As before, he read carefully with a pencil and two different pens ready to hand for needed annotations and comments. He left scarcely a page of Truesdell’s book unmarked, underlining in red, green, and pencil, though he reserved pencil for his marginalia: “from what?: evidently [arrow pointing above] since Taylor’s analysis was for a horiz. stretched string.”

As usual, our historian happily marked up his book with pens and a pencil.
As usual, our historian happily marked up his book with pens and a pencil.

His marginal notes were not confined to a single page. Using a detailed set of footnotes, he often cross-referenced other pages in the book:

*Formally this is what it was; and E. proposed a formula which gave the “potential live force” from the “force of elasticity” (bending movement), but there is no trace of the work concept as such. See p. 218.

On page 218 he dutifully noted the reference on 425.

And he added footnotes and internal references.
And he added footnotes and internal references.

And, as was his habit, he used the opportunity to reflect on broader questions. In this case, he wondered about the relationship between mathematics and reality:

And thus, I suspect, a lesson in the relations bet math theory & practice: If the theory allows a solu, it is likely to be realized in fact—somewhere, somehow.

He also added general, philosophical commentary, where needed.
He also added general, philosophical commentary, where needed.

Like a modern Menocchio, Ginzburg’s famous miller (see Perry Anderson’s review of Ginzburg’s latest book), our physicist-turned-historian of science pieced together a cosmology from his wide and eclectic reading, a cosmology that structured his world in a way that allowed Velikovsky to exist alongside Kuhn and in which the boundary separating natural from supernatural was a contested.