The Chronology of Second Century Ptolemaic Bronze Coins:
Two Different Methods to Graphically Interpret Weight/Size Data

Graphing of weight data versus Svoronos numbers gives an illustration of the chronology of 2nd century bronze coinage

 

This page, and the parts that follow, show that F&L's weight and size data can be used with Svoronos' numbers not only to give an illustration of the relative chronology of second century bronze coinage but also to give corrections to F&L's reattributions of several types of coins.

As shown below, the chronological aspect of the types can be made numeric by the use of Svoronos numbers and the result is a graphic illustration (see RP-Graph-1, left) of the weight versus chronology of second century Ptolemaic bronze coinage.

Click here to see a larger image of RP-Graph-1

Svoronos’ catalogue numbers are widely used to indicate a specific type of coin listed in his monumental compilation of Ptolemaic coins. His cataloguing placed related coins into series with later series having greater Svoronos numbers. Therefore, a Svoronos number not only indicates a specific coin type but may also give a distinct numeric indication of relative chronology that can be used in scatter graphing. However, adjustments must first be made to those few Svoronos numbers where attributions have been changed (mainly because of new hoard data) since production of his catalogue in 1904. Then, for each type of coin in the data tables, Svoronos numbers are used with scatter graphing to give a meaningful presentation of average weights (g) versus chronology (Sv numbers); the results are shown in RP Graph 1 above.

 

Click  RP ANALYSIS  to see the method of development of RP Graph 1

 

The well-organized pattern with cohesive columns of data-points in RP Graph 1 successfully shows the various series of related coins produced during periods involving four consecutive regencies. They are, from left to right the ‘helmeted head’ series with the Athena head coin of Ptolemy IV (c.205 BC); the so-called Isis series of Ptolemy V (204-180 BC); the Necropolis hoard coins of Ptolemy V (204-180 BC) and of Ptolemy VI (after 180 BC); the coins of Ptolemy VI (180-170 BC) with co-regent Cleopatra I (180-176 BC); and, finally on the right, three examples of coins with the two-eagle reverse type produced by Ptolemy VI (180-c.170) and continuing with co-regent Ptolemy VIII (before 164 BC).

RP Graph 1 shows average coin weights according to the relative chronology (from c.205 to c.164 BC) implicit in Svoronos numbers. RP Graph 1 does not ‘prove’ Svoronos’ assignments. It illustrates a chronological pattern where all the weight/size data are consistent with updated attributions and, in contrast to F&L Table 3, are also in agreement with all previously accepted attributions.