From Thomas Jefferson to James Oldham, 29 May 1803
To James Oldham
Washington May 29. 1803
Sir
On the 26th. inst. there were shipped from Philadelphia 2 boxes of sheet iron for the terras, bent & painted ready to be laid. these contain 39. sheets only. for the terras it will take
| 96. | sheets in the whole and | |
| 20. | do. for the 8. gutturs of the porticos & piazzas | |
| 3. | do. for the gutturs where the roof joins the walls of the dome room | |
| 119 | in the whole. |
so that about a third only of the whole is shipped; this will cover about 25. f. in length of the terras. the rest are promised as fast as they can be prepared. I am informed however that these sheets are not in one piece each, but in two put together with a tuck thus 
consequently you must observe to put the proper end uppermost. I will direct them, as soon as they have 60. sheets more ready, to send them off, that the terras may be compleated. those for the gutturs of the porticos &c [ma]y come last.
I have this day calculated the number of pannels &c of the ballustrade, & find [th]ere will be 26. pannels of from 5. to 6. ballusters each, 8 pilasters of 2f—6I and 24. do. of 2. feet breadth each. the thickness of the pilasters double that of the balluster. this will take in the whole 136. ballusters, but say 150. but this is on the supposition the ballusters are 5. I. thick, as I believe they are, for I have no note of them here, and am not very certain in my recollection of them. if they are smaller or larger, they will take more or fewer exactly in proportion to the error I commit in estimating their size: for instance if they are only 4. I. diameter, then it will take 5. for every 4. of my estimate, that is to say 188 instead of 150.
I think it would be better to use these first sheets over the hall, leaving the two ends of the terras to be done last: because these will compleatly cover the hall, so that the work in it may be begun. Accept my best wishes
Th: Jefferson
P.S. on second thoughts I will direct the sheets to be forwarded in parcels of 30. as fast as done, because each 30. will finish one end of the terras, the middle part being covered with those now sent.
RC (MHi: Frothingham Papers); torn; addressed: “Mr. James Oldham Monticello near Milton”; franked; postmarked 30 May.
Benjamin Henry Latrobe was supplying TJ with sheet iron (Vol. 39:257n). A letter of 26 May from Latrobe, recorded in SJL as received 28 May, has not been found.
TJ designed a ballustrade running along the top of Monticello’s exterior walls, where they joined the lower portion of the roof. Undated design notes in his hand reflected the calculations above, with 33 balusters divided into 6 panels on the west and south angles, 35 balusters divided into 7 panels on the east and north angles, and 8 pilasters on each side. For some time, workmen at Monticello had been producing balusters with a lathe, but the project took a number of years to complete, and TJ may have modified some of his calculations. At the bottom of his notes he appended on 17 Sep. 1805, “the ballusters on actual measurement are 30. I. high & 5¾ I. diam. or square. the spaces between them may be <3. I. to avoid [. . .] or even 3½ I.> the half of the diameter.” A sketch of the cap and base of the balustrade, accompanied by some design notes on the balusters, also indicated that each would have a diameter of 5¾ inches, separated from one another by half as much space (, 265–6; “Monticello: notebook of improvements” [1804–1807], in MHi; “Monticello: architectural detail [top of house], [1803],” in same; , Nos. 159 and 171; Vol. 39:99n).