Thomas Jefferson Papers
Documents filtered by: Author="Jefferson, Thomas" AND Recipient="Brockenbrough, Arthur S." AND Period="post-Madison Presidency"
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From Thomas Jefferson to Arthur S. Brockenbrough, 1821

Th:J. to mr Brockenbrough

Palladio’s measures of the Fortuna virilis are not in Modules & minutes but in quarter inches of the Vicentina foot, the diameter of the column being 2 f–8½ I or 130 quarter inches which he calls minutes. then 130 ¼ I : 60′ :: 95 ¼ I his projection to 4317/20′ which is the projection of that cornice given by Palladio.

Chambray’s drawing of the same temple being expressed in modules and minutes, I had taken the projection of the cornice from his notation of 70′ .measured from the center of the column. but measuring the projection from the face of the frize or of the diminished diameter as I generally do, one half of the diminished diameter, to wit, 26½′ must be deducted from Chambray’s 70′, which leaves for the projection of the cornice beyond the face of the frize 43½′ = 21¾′

so that the projection,  if measured from the center of the column is 1 m – 10′ = 2 f—11 I as noted
but  if measured from the face of the frize is 43½′ = 1 f – 9¾ I

the difference between Palladio’s and Chambray’s projections is by 1/10 of a minute.

ViU: Thomas Jefferson Papers (Proctor’s Papers).

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