Table of Values of European coins about 1800
We know from our research of coin catalogs what the face value of various coins and can calculate from their theoretical exchange ratio from their bullion content. It is instructive to look at primary documents to see how merchants dealt with various coins that came across their counters. The first thing any merchant would have done to any coin he was not familiar with would be to weigh it, perhaps with a scale similar to the one shown here.This scale is labeled in French so we assume that it was used there. The label is headed,
"Table des Monnaies d'Or qui ont cours dans les different Etats de l'Europe, avec la designation de leurs poids. (Table of gold coins current in the different countries of Europe with the designation of their weights."Four columns are shown, each labeled in "gro" (Gros) and "gra" (Grains). Altho the metric system was in legal force in France at this time, it doesn't seem to have penetrated to this merchant's counting offices. We will attempt to calculate the size of these obsolete units below.
The first column mentions four coins, which we translate below. We expand the abbreviations inside the brackets :
- Louis v[ieille]. de 48 l[ivres tournois]. 4 gros & 18 gra (this would be the old double louis d'or of 1726-85 of 16.31 g, .917 fine gold);
- Louis v[ieille]. de 24 l[ivres tournois]. 2 gros & 9 gra (this would be the old louis d'or of 1726-85 of 8.15 g, .917 fine gold);
- Louis n[ouveau]. de 48 l[ivres tournois]. 4 gros (this would be the new double Louis d'or of 1785-92 of 15.29 g, .917 fine gold);
- Louis n[ouveau]. de 24 l[ivres tournois]. 2 gros (this would be the new louis d'or of 1785-92 of 7.65 g, .917 fine gold).
The second column mentions four coins, two of which are actually silver:
- Ecus de 5 liv[res tournois] de France 7½ gros & 12 gra (this is the écu aux branches d'olivier struck 1726-92 of 29.48 g, .917 fine silver);
- Piece de 5 fr[ancs] de France 6½ gros & 6 gra (this is the "Hercules" five francs struck years 4-11 of the revolutionary calendar. It weighed 25 g, .900 fine silver);
- Guinée d'Ang[leterre] 2 gros & 12 gra (the English guinea of 8.35 g, .917 fine gold);
- Quadru[ple] d'Espag[ne] 7 gros & 3 gra (probably the Spanish doubloon or eight escudos of 27.07 g, .875 fine gold).
The third column mentions six coins as follows:
- Ducat d'Hol[lande]. 66 gra (the Dutch ducat of 3.5 g, .986 fine gold);
- Ducat d'Aut[riche]. 66 gra (the Austrian ducat of the same weight);
- Sequin de Rom 2 gros & 60 gra (an Italian coin);
- Pistole de Pié[monte] 2 gros & 24 gra (the Sardinian doppia, 9.116 g, .905 fine gold);
- on[cia] de si[cilie] 2 gros & 22 gra (the gold oncia of Sicily, 3.78 g, .996 fine gold);
- Souver[ain] de Flan[dre] 2 gros & 60 gra (the souverain d'or of the Austrian Netherlands, now Belgium; 11.06 g, .919 fine gold).
The fourth column mentions five coins as follows:
- Piece de Parme 1 gros & 60 gra (perhaps a doppia of the duchy of Parma, 7.14 g, .891 fine gold);
- Piece de Prusse 1 gros & 54 gra (the Prussian friedrichs d'or, 6.682 g, .903 fine gold);
- Portug. 1 gro & 54 gra (probably the Portuguese 3200 réis, 7.15 g, .917 fine gold);
- Piece de Géne[ve] 6 gros & 39 gra (perhaps a Genevan pistole, rather light at 7.64 g, .900 fine gold);
- Milleret de Portugal 2 gros (perhaps the Brazilian 4000 réis, 8.07 g, .917 fine gold).
"12 grains d'Or valent 2 liv[res tournois], 6 grains d'Or valent 1 liv[re tournois]., 1 grain d'Or vaut 5 sols 4 deniers (twelve grains of gold are worth two livres tournois, six grains of gold are worth one livre tournois, one grain of gold is worth five sous and four deniers.)"In the old French system, one livre was twenty sous and one sou was twelve deniers.
Estimated date of manufacture
The printed legend mentions the French silver five francs (first issued 1795) but not the French gold twenty francs (first issued 1803). The twenty francs or napoleon was minted in large numbers and quickly drove the old royal coins from circulation; its omission from the list puts a terminus ad quem on when this scale was made.
Weights and measures used
The measurements used here, gros and grains, are now obsolete. The grain in the English and American avoirdupois system is exactly 1/7000 of a pound or 64.8 mg. This is manifestly too high as that would make the Dutch ducat weigh 66 gr. x 64.8 mg = 4.28 g when its actual weight was 3.45-3.50 g. Calculating from the Louis d'or of 2 gros = 144 grains = 7.65 grams, we estimate that the grain was 54.6 mg and the gros was 3.825 g. This makes the French écu, the five francs and the English guinea come out fairly close to their correct values. If this is correct, the ducat should be about 64 grains, not 66. Another source of uncertainty is the tendency of governments to issue coins on the light side of the tolerance; we don't know if the maker of the scale used the government (nominal) weight or the actual weight in preparing his chart.
1 livre = 2 marcs; 1 marc = 8 onces (244.7 g); 1 once = 8 gros; 1 gros = 3 deniers; 1 denier = 24 grains; 1 grain = 53 mg.