NAS Committees Advisory to Government 1863-1913

The National Academy of Sciences’ Committee on Materials for the Manufacture of Cent Coins

This committee, which was misnamed in the reports of the Academy, was appointed on April 11, 1864, at the request of the Secretary of the Treasury, Salmon P. Chase, “to examine and report upon aluminum bronze, and other materials for the manufacture of cent coins.” [Ann. Nat. Acad. Sci. for 1863-1864, p. 40.] It consisted of John Torrey (chairman), Joseph Henry, Wolcott Gibbs, F.A.P. Barnard and the President, A.D. Bache, who was added by request of the Treasury Department. The phrase from the first Annual of the Academy, quoted above, defining the duties of the committee, though occurring in substantially the same form in the report of the President of the Academy, appears not to be quite accurate. If it be so, it may indicate that the views of the Secretary of the Treasury and the Director of the Mint were not entirely in accord regarding the cent coinage. The latter in his report for 1864 remarks: “During the pas year some interesting experiments were made with aluminum as an alloy for coins; not with a view to displace the bronze coinage, but to propose a system of tokens for five and ten cents.” [Rep. Dir. Of the Mint in Rep. Secr. Treas. For 1864, p. 214.] It is not surprising that the Director of the Mint should not have contemplated a change in the bronze coinage at that date, as the Government had just adopted bronze once cent and two cent pieces, more than 42,000,000 of the former and about 2,000,000 of the latter having been coined in 1864. It would seem that the idea was not at all to displace these new and popular coins, but rather to determine the properties of aluminum bronzes, particularly with a view of employing them for other forms of currency. The experiments were suggested by certain claims put forward in France that a small percentage of aluminum added to silver would prevent the latter from tarnishing when exposed to fumes containing sulfur, while at the same time forming an alloy of considerable hardness.

While the committee had the subject under consideration an article on aluminum bronzes was published by Moreau, and it was found that he had fully covered all the points regarding the characteristics of those alloys which the committee was to investigate. The proceedings were on this account confined simply to preparing a bar of aluminum bronze, and having coins struck from it at the mint in order to ascertain to what extent the alloy was suitable for coinage. The bar was prepared by Joseph Saxton, a member of the Academy, and transmitted by Joseph Henry to the Director of the Mint, who in turn placed it in the hands of the assayer, J.R. Eckfeldt. The report of the Director of the Mint, James Pollock, contains a statement regarding the nature of the experiments which were made with this bar, the results obtained, and the conclusions derived therefrom. He first remarks that experiments had been made two years previously to determine whether aluminum bronzed could be used for medals, that they had resulted negatively, and that then the use of such alloys for coins had been suggested. He continues:

“A further series of experiments was therefore undertaken here, at the desire of the Secretary of the Treasury and a committee of scientific gentlemen. The latter forwarded to the mint a bar for this purpose, which, by assay, was found to contain the proportion of nine parts copper to one of aluminum. Their directions were closely followed and the principal results may be briefly stated as follows:

‘The aluminum bronze, in the proportion just stated, is very rigid under the oblique fracture….This hardness gives it a great advantage in wear. Coins of the cent size were made of this alloy, of legal bronze, and pure copper. The three varieties placed in boxes and rapidly shaken for a long time, treated equally in all respects, lost by attrition in the following ration: Assuming the aluminum bronze as the standard of comparison, the legal bronze lost abut three times, and the copper about six times as much. This property, however, is of no great consequence in coins of little value.

“A point of much greater consideration is the avoidance or mitigation of the tendency to change color and become fouled from the usual causes, viz., the action of oily and saline excretions of the hand; the chemical agencies which are met with in market-stalls, and the slops of drinking saloons, and the mere exposure to air and moisture. If any metal or alloy could be found that would look well, and keep clean with the usage to which our small coins are generally subjected, it would be deservedly popular. This can be scarcely expected. A silver coin can be deprived of its original beauty and become of such a hue as to have its genuineness called into question. Pure aluminum, white at first, assumes a bluish tint by atmospheric actions; and aluminum bronze, although closely resembling gold at first, was found, after being held in the sweaty hand for a few hours, to have received an ugly tarnish which destroyed the last argument for employing it in currency.

“After these experiments were concluded others were started, in the hope of finding a binary or ternary alloy which would answer the required conditions, especially as to ductility and keeping color for coins of a grade a little above the cent and two cent pieces. After some progress had been made, it became evident, from the fact that cents were hoarded to such an extent as to keep them out of circulation, that in the present state of the currency it would be futile to attempt to carry out this project. More than this: we believe the end of our nation’s troubles is nigh, and that peace will soon bless our country. With peace we may confidently expect an influx of silver, always more acceptable than any substitute, which will supply every want and furnish a currency of ‘small coins’ equal to any demand.” [Rep Secr. Treas. For 1864, pp. 214-215. The report of the assayer to the committee of the Academy, which contains many interesting details, is given in full in the annual Report of the Academy for 1864, pp. 8-10.]

Pollock’s prophecy as to the return of peace and the return of fractional silver currency into circulation were both fulfilled, and further experiments with aluminum alloys became unnecessary. The work of this committee of the Academy, which was indeed limited in extent, led, therefore, to no practical results.