3d. For Tens, two Places, thus: 204.1 becomes 2.041:

4th. For Units, three Places, thus: 340.1 becomes .3401:

5th. And for each Decimal, a Place more, by adding Cyphers to the left, if wanted, thus: 68.0 becomes .00680.

407. Place the plain and decimated Answers, in one View, and add the latter together, thus:

204.1 =

the same 204.1

612.3 =

becomes 61.23

204.1 =

2.041

340.1 =

.3401

68.0 =

.00680

—————
viz. Expansion of Air with
28° on 3935.1
267.7|179

408.

Second, with .71° on Feet 3000 =517.5
900 as 9000 =1552.7
30 3000 =517.5
5 5000 =862.6
.1 1000 =172.5

In order to decimate these Answers, it must be observed that the Expansion was not with 71 Degrees, but with .71 Tenths of a Degree of Heat; therefore the decimal Point corresponding to 3000 Feet in the Question, must in the Answer be removed two Places to the left, thus: 517.5

becomes 5.175: for the 100, three Places: for the 10, four Places: and so on.
1.5527
.05175
.008626
.0001725
—————
6.7|882485

The Expansion with .71 being found, viz. Feet 6.7 Tenths; add it to the Expansion on 28 Feet already found, viz.