These _Rods_ of _Copper_ are (as I told you in §. III. ¶. 1.) to be Cut into small Lengths, each about an Inch and an half long, and a _Great-Primmer_ or _Double-Pica_ deep; and for great Bodyed _Letters_ a _Two-lin’d-English_ deep; But their Thickness not assignable, because of the Different Thicknesses in _Letters_, both of the same and other _Bodies_, as in part I shewed, in §. II. and more fully in this present §. and ¶. The reason why the _Copper-Rods_ are Forg’d so deep, is, That the more substance of _Copper_ may lie under the _Face_ of the _Punch_: For if the _Rod_ have not a convenient depth, the _Face_ of the _Punch_ in _Sinking_, does the sooner ingage with the Hardness of the _Face_ of the _Stake_ it is _Sunk_ upon: And having with a few Blows of the _Hammer_, soon hardned the _Copper_ just under the _Face_ of the _Punch_, as well the hardness of the small (thus hardned) _Body_ of _Copper_ just under the _Face_ of the _Punch_, as the Hardness of the _Face_ of the _Stake_ contribute a complycated assistance to the breaking or battering the _Face_ of the _Punch_. But if the _Rod_ be deep, the Substance of _Copper_ between the _Face_ of the _Punch_ and the _Stake_ is less hardned, and consequently the _Punch_ will _Sink_ the easier, and deeper with less Violence. But sometimes it has happ’ned that for the _Sinking_ one _Matrice_ or two, I have been loath to trouble my self to go to the _Copper-Smiths_, to get one Forg’d: and therefore I have made shift with such _Copper_ as I have had by me. But when it has not been so deep as I could have wisht it, I have just entred the _Punch_ into the _Matrice_ upon the _Stake_, and to _Sink_ it deep enough, I have laid it upon a good thick piece of _Lead_, which by reason of its softness has not hardned the _Copper_ just under the _Face_ of the _Punch_; but suffered the _Punch_ to do its _Office_ with good Success.