Germany, 1820: Mechaniker Apel of Göttingen (Brunswick)

Göttingen (now Lower Saxony) was in the Kingdom of Hanover, whose Prince Elector was then George IV (UK.)  Hanover weights and currency vary slightly from Prussian and Convention-standards.

October, 1820: 1 Troy Ounce Platinum (Göttingen Retail) = Thlr 6.385
.... Frankfort a.M :~Rthlr C.M. 7.09 , Fl. 17.03 ; ℳ C. 24.20, London: £ 1.064 ; Paris: Fr. 26.18

c.1819: 1 Troy Oz. Platinum (UK: pre-import; English mfg)  = £ 1.0 (Thlr 6.32)

1819: 1 Troy Oz. Platinum (Paris: refined) = Fr 18.29 (USD$ 3.42)  
 

"English" Platinum appears cheap in Apel's advertisement.  It's doubtful a merchant in Göttingen could procure English Platinum with such economy.  In Late 1820, Wollaston noted Cary's purchase of French Platinum @ Fr 18.10 ; he himself concluded his own Platinum refining enterprise that year for want of cheap platina.   

Where the January 1820 rate was Rthlr 6.32 per £ 1. or Fr 3.76 per Rthlr. 1.0,  

In a South German university town, it seems most likely Apel offered French Platinum wire &sheet with a ~45% mark-up over the French source, not factoring any discount. 
 
"...thick wire & sheet of the best {imported} English Platinum, sold by the Loth: 3 Thlr."

Citation: Allgemeiner anzeiger und nationalzeitung der Deutschen(1820) p.2992



Where the Hannover Kölnische Mark (16 Loth) = 233.826 g. or 7.5177 Ozt, 1 Hannover Loth = 14.614 g.  or ~0.47 Ozt. ; 1 English Troy Ounce ~ 2.1283 Hannover Loth. 


Heavier than the Convention Thaler (rated 1.1111 more valuable), the Hanover Gold Thaler was ~Fr. 4.10 (c.1820)

The Hanover Silver Thaler (Fine Ag: ~26.069 g., 0.838 Ozt) was rated 3.79x more valuable than the Hambourg Mark-Current ; likewise ℳ 1. ~Fr. 1.532.

In Brunswick money (1820) 1 Kilogram Pt cost 3.44 Kg (110.6 Ozt) Fine Ag or 0.243 Kg. (7.802 Ozt) Fine Au, a PM ratio of 1: 4.121: 14.174

The commercial Loth weighed 15.3 Grams; the Cologne Marc Loth weighed 14.6 Grams. 
In Hamburg Marks-Banco at the Apothecary Loth rate (1820) 1 Kilogram of Platinum cost ~ℳ 418.78

Frankfurt: Johann Valentin Albert

 



Notices
Platinum vessels 
In the ""Allgemeinen Handlungszeitung"" Issue 208 (or on the 22th of October) b. J. mentioned Platinum vessels as dishes, crucibles, spatula bucket as well as pliers and tweezers, wire the finest and thicker for pre-drilling the flash holes on hunting rifles sheet to show the pan-bore, Platina-plate to incandescent lamps are in addition to those to have new metals and metalloids in Johann Valentin Albert in Frankfurt a.M.
 

Also seems Apel to have been the first who established (probably on Haussmann's instigation, we have to be regarded as the father of mineralogists school in Göttingen) one of those times extremely diverse range of mineralogical Help sapparaten and utensils, and brought into the trade. In 1821 leads Apel blow-pipes, tongs and crucibles of platinum, reflection and Anlegegoniometer in various models and divisions, and also of English steel hammers, compasses, rich mineralogical cutlery, hydrometers, small hydrostatic carriage provisions to the specific weight.  Apel as estimated in these efforts was his, even far beyond the walls of Göttingen, teaches the fact that in 1825 the Mineralogical Society of Jena, whose president was none other than the great Goethe, appointed the "famous university mechanic and mineralogist Friedrich Mr. Apel" their esteemed foreign member).

Erroneously cited and repeated in German journals (1821 - 1822) reference to William Cary was dated information from 1819.   In fact Cary's address had changed by January, 1820.

The cited price in Thalers is simply forex, not accounting for the total cost of shipping nor insurance. 

The French price peaked in 1825; Platinum from Paris certainly rose higher elsewhere.  That Sterling & Thaler Platinum prices were nearly identical in 1819 suggests a French price quote from that year.

c.1819/20: 1 Troy Oz. Platinum (semi-mfg, London)  ~ Thl 6.38 (USD$ 4.66)

Citation: Allgemeine deutsche Real-Enzyklopädie für die gebildeten Stände ... (1824) p.606