Thomas Jefferson Papers
Note: this document has content that may require expanded/print view for best results (icons above right)

Notes on the Canal Locks and Manufacturing Mill at Shadwell

Measures taken at the locks & large mill, by myself May 11. 17.

the water was running 4½ I. deep over the waste.

 surface of water in canal above that in upper chamber 8¼ I 0–8 ½ depth of water in upper chamber, from it’s surface to it’s floor 6 f. 6 I. 6–6 middle do do 1–4 lowest do do 1–8 clear lift of middle lock 7.f. 6 I. 7–6 Lowest do 7 f 8 I deduct depth of water—leaves 6–0 clear width of the chambers 8.f. 20–4 ½ each recess is 9.I. deduct depth on waste 4 ½ clear width at recesses 9 f. 6 20–0 clear length of each chamber inside 68.f. 6.I. f the floor of the lowest chamber being 1.f. too high, call the whole 21–0 then 3. lifts of 7.f. each accomplishes it

 Mill from surface of water in the canal to bottom of forebay or top of wheel 2 f 9I. diam. of wheel 14.f. 14 –0 bottom of wheel above surface of river at the tail 2.f. 2 18 –9 deduct depth of water on the waste 4½ leaves height of waste above the surface of the river at the tail 18 –4½ height of waste above surface of river at the tail of the lock as above 20 –0 this diffce may be the fall in the river from tail of lock to tail of mill. 1 –7½′1

 Stone work for locks of 3. chambers of 7.f. lift each. exclusive of foundations. f 3. chambers of 70.f. length clear, for both sides 420 38. abutments @ 11 f–8. I apart, 8.f. long at bottom 4.f. at top say 6.f. 228 perch running measure 648 = 40. thickness 4.f. at bottom, 2.f. at top. say 3.f. × 40 = 120. height above foundation, or floor 10 f. × 120. 1200. 4. breast walls 16.f. long. make 64.f. running measure = 3.75 perch. 4. f. thick 15. 7. f. high. say for round numbers 100. 1300. perch.
 D Stone mason for laying @ .75 975. lime & planter’s work @ 1.75 2275. ) by myself. Carpenter’s & Smith’s work & digging

 Suppose the foundation of the lower lock sufficient, & the others going down to that foundation of middle chamber 7 f below it’s floor is 140 f = 8½ perch × 4 × 7 = 238. perch. it’s breast 1. perch long, 4.f. thick, 7.f. to the floor 28 foundation of upper chamber 14.f below it’s floor is 140 f = 8½ perch × 4 × 14 = 476 it’s 2. breasts, 1. perch long, 4 f. thick 14.f. high is 140 f = 8½ × 4 × 14 = 112 854.
 D Mason @ .75 640 lime and planter’s work @ 1.75 1494. by myself 2134

 D All together work done by the mason 975 + 640. = 1615 by myself 2275 + 1494 = 3769 ) D 5384 = 4385. by myself suppose Carpenter’s & smith’s work & digging worth 616 6000

(); written entirely in TJ’s hand on both sides of a single sheet; paper watermarked 1794.

1Recto ends here, with last line of text trimmed but legible.

Index Entries

• building materials; lime (mineral) search
• building materials; stone search
• canals; at Shadwell mills search
• Jefferson, Thomas; Writings; Notes on the Canal Locks and Manufacturing Mill at Shadwell search
• lime (mineral); as building material search
• Shadwell mills; canal at search
• Shadwell mills; manufacturing mill at search