Top Dr. Christopher Wren's Engin, designed for Grinding Hyperbolical Glases.⁠

Fig 1 - 6 Explication of the Figures belonging to the Accompt of Salt-making.

Fig. 1.This is the Model of an Iron-pann of that proportion, when Four are used in one house.

a a. The Eares to hang the Pann by upon the Brick work.

b. The several Junctures of the Iron plates riveted.

C C. The breadth and length of the Pann near 4. foot.

C d. The depth of the sides of the Pann, about 6. inches.

Fig. 2.a a. The Hot-house between the Wall and the Chimney.

b b. The two Tunnels.

C C. The Chimney-back, into which the two Tunnels conveigh the smoake.

d d d. d. The four Panns.

E. The partition-wall between the Panns and the Hot-house.

f. The Fire-places.

g g. The Ash-holes.

h. The Hearth below.

i i. The descent to the Hearth.

Fig. 3.The Back with his stale, with which they reach brine our of their Ship to fill their Panns withall.

Fig. 4.a. b. Several positions of their Loots, with which they skim, and gather their Salt.

Fig. 5.a.a. Two Barrows newly filled with Salt; set into the Leach-trough to dripp out the Leach or Leak-brine.

b b. The Salt heaped above the Barrows and patted dawn hard.

C. The Leach trough.