1836 - Improved coinage through steam engine power...?

[RWB]

Comments are welcome on the following statements:

 

Many numismatic writers have emphasized improvements in U.S. coinage due to the change to steam engine power. The transition can be clearly seen in differences between half dollars of 1835 and reeded edge halves of 1836-1837. But the change that brought about the differences in appearance – specifically uniform diameter and reeded edge – was not use of steam power. It was the use of Peale’s knuckle-type press. As Peale notes in a short article in the Journal of the Franklin Institute (1836, pp.306-310):

 

“The design exhibits the general proportions and arrangement of parts consisting of a shaft with a fast and loose pulley to receive motion by means of a strap from the moving power, whether water, steam, horse or hand: the latter, of course, being least desirable, will only be used, when neither of the others is available.”

 

It was the action of the press, not of the steam engine, that permitted round coins and reeded edges. As Peale noted, any kind of power source could operate his coin press – even human muscle.

 

[zeewool]

the change that brought about the differences in appearance – specifically uniform diameter and reeded edge – was not use of steam power. It was the use of Peale’s knuckle-type press.

 

Exactly...... which should be common sense....... but it is amazing just how much misinformation can be generated through the pipe dreams of prolific numismatic authors.

 

"Water, steam, horse or hand" are all simply methods of generating movement, but have absolutely nothing to do with alignment or uniformity.

[DWLange]

Quite true. It was the progressive squeezing action of the knuckle press that imparted fuller strikes that the abrupt blow of the screw press. The Mint gradually learned to take the greatest advantage of this by including a slight convexity to the die faces, which had hitherto been quite flat in their fields.

[shirohniichan]

And now new collectors will know why their early half dollars don't always fit in their Danscos as well as the steam-press-struck capped bust examples. It warn't the steam!

[PerryHall]

And now new collectors will know why their early half dollars don't always fit in their Danscos as well as the steam-press-struck capped bust examples. It warn't the steam!

 

Yup---it was the lack of a collar holding the planchet which controlled the lateral expansion of the coin during striking.

[johnny9434]

interesting material. thanks for sharing

[Berean-migration]

Was that in conjunction with the closed collar? What year was the press introduced? Must have been different years for different denominations. As noted above, the halves changed in 1836, but weren't all the other denominations struck with a closed collar by 1828-1831?

[RWB]

In early 1836 there was one working knuckle-type press and more being built. The reeded collar die was always used with Pleale's knuckle-type press - drawings indicate it would not operate properly with an open collar.

 

As for earlier collar changes, etc., Bob Julian can provide much better information than I can.

 

[Conder101]

Close collars were introduced earlier. In fact the very earliest reeded edge coins in 1795 had their edges applied by a collar.

[DaveG]

My impression is that I've always read of the introduction of the "steam press", (which was of a different design than the screw press).

 

As a result, I've always thought of 'the press that was introduced at the same time as the steam engine' that resulted in the differences in coinage; and, therefore, I didn't place emphasis on the means by which the power was provided to the press.

 

That having been said, I agree that the knuckle press should have its due (along with the closed collar)!

[RWB]

In Peale's knuckle-press design the massive fly wheel stored energy. Only when the press mechanism was engaged did the fly wheel energy get used, in part, to operate the mechanism and strike a coin. The total energy store by the fly wheel was far greater than that need to rotate the toggle joint, and this allowed smooth operation of the press. The power source - muscle, steam engine, electric motor - only served to renew the energy lost to the press mechanism.

 

Peale translated Bolton's weighted, intermittent action, screw press arms into the constantly rotating fly wheel. This use was common to many machines and was part of the German and French press designs of the 1820-30s.

 

[disme]

One of the more interesting aspects of the screw press is that it was used

well beyond 1836 for medals and proof coins. It was not until January 1894

that an hydraulic press began to be used for these purposes.

[RWB]

Yes, they were still in regular use in 1902 and probably later.

[DaveG]

Actually, now that I think about it, I recall a post ( ATS ) that included in illustration of a steam-powered screw press.

 

It does serve to illustrate that it wasn't the source of the power, but rather the change in press design that was important. (Although, the Boulton coinage was, by and large, extremely well produced.)

[Conder101]

The advantage of the steam operated screw press was that the steam engine could operate faster and didn't get tired. No rest breaks and more uniform striking.

 

I understand how his circular striking arrangement worked withthe overhead drive wheel but I'm not sure how he linked his later linear strike arrangement to the power source. I don't believe I have seen drawing of how he did that.

[RWB]

See this post "Steam Powered Screw Press" from Sept for an engraving of the screw press.

[coinman1794]

...horse or hand: the latter, of course, being least desirable

 

Horse and hand power was less consistent than steam. It is the close collar technology that made reeded edges possible, and steam power that regulated the machinery enough to make coins more efficiently, and ultimately to more precise specifications, as the technology improved.