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

An analysis of weight/size data shows that there are serious flaws in a recently presented chronology for 2nd century bronze coinage

 

The graphing of the data from F&L's Table of Hoards occurs when the consecutive average weights from the listing are placed in each of seven horizontal positions from left to right (seven sub-series labelled 6a, 6b, 6c, 6d, 6e, 7a, and 7b). The verticle positions of the coins in the graph are based on factual data (the weights from 2g to 40g); the horizontal positions (6a to 7b) are hypothetical.

It is the order of the weights in F&L's Table of Hoards listing that creates F&L Table 2. Although the Zeus-Ammon/double-eagle hypothesis was applied in the listing, it was not mentioned how the "proper" sequence in the list was obtained from hoards.

F&L state that the types must have been critical for recognizing the various denominations and The following table [F&L Table 2] takes account of obverse types only.

F&L Table 2. Proposed subdivisions of Series 6
WEIGHT 6a 6b 6c 6d 6e 7a 7b

38-40g

LH-Ammon Sv1423

Ammon Sv1423 

 

 

 

 

 

30g

Isis   Sv1491

Isis Sv1233

Ammon Sv1424A

 

 

 

 

22-24g

 

 

 

Ammon Sv1375

Ammon Herakleion

Ammon Sv1380

Ammon Sv1383

17-20g

Heracles Sv1497,1492

 

 

 

Isis Sv1234

 

 

15g

Alexandria Sv1493

 

 

 

 

 

Isis Sv1384

11g

 

 

Heracles Sv1494

Heracles Sv1376

 

 

Heracles Sv1385

8-9g

 

 

Alexandria Sv1495

 

Alexandria Sv1236

 

 

6-7g

Isis   Sv1154

Ammon Sv1173

Ammon Necropolis

Ammon Sv1377

 

Alexandria Sv1381

Alexandria Sv1386

4-5g

Heracles Sv1496

Helmented bust Sv1155

 

Nilus? Sv1378

Isis Sv1238

Isis Sv1232

Isis Sv1287

2.4-3g

 

 

 

Helmented bust Sv1379

Helmented head Sv1156

 

 

2g

 

 

Athena Sv1195

 

 

 

 

The Ammon coins at the top of each column in F&L Table 2 show weight reductions for the Zeus-Ammon/double-eagle type, i.e., there are reductions from 6b to 6c and then to 6d. Within the various columns from left to right there are similar reductions in weight for each of the types Isis, Heracles, Alexandria, and Helmeted bust.
    These weight differences are interpreted by F&L as piecemeal weight reductions of coins with the same obverse type representing the same denomination during various progressive periods from c.204 to 116 BC.

 

 The ten distinct modules discerned from F&L Graph 1 are shown in F&L Table 2 (above) to be distinct denominations by weight/size

By the highlighting of F&L Table 2 with eleven different colours it is seen that there are eleven different denominations by weight/size. These are the ten different denominations recognized by F&L from their Graph 1, together with the single data point for the Athena denomination.

Rather than piecemeal weight reduction for coins with the same obverse, F&L Table 2 shows denominational recognition by weights/sizes. The table also gives evidence against denominational marking by obverse types.

For example, the Zeus-Ammon/double-eagle coins, that are hypothetically all stated to be the same denomination with reduced weights, are placed in the listing of F&L's Table of Hoards at the top of each sub-series 6a to 7b. After graphing of the list, these coins appear in three different weight/size positions and, by classical determinations, these three vertical positions are three different denominations of the Zeus-Ammon/double-eagle coins (i.e., not all the same denomination). In addition, and contrary to denominational indication by obverse types, in F&L Table 2 five of the eleven rows show coins of the same denomination (same weight/size) with different obverses (see weights of 30, 17-20, 15, 6-7, and 4-5 g).

This table is all in accord with the classical view that denominations are determined by weight/size and not by obverse types. The graphing of the list of data from the Table of Hoards, that is said to establish the relative chronology of the series, results in a pattern (F&L Table 2) that fits determination of denominations by weight/size: It should be concluded that the hypothesis of obverse marking and piecemeal weight reduction can not be supported by F&L Table 2.

Nevertheless, F&L present the additional Table 3 [that] is a reorganized version of Table 2, [by again] using obverse types as the main criterion. Click F&L ANALYSIS (below) to compare this new F&L Table 3 with F&L Table 2.

Click  F&L ANALYSIS  to compare F&L Table 2 with F&L Table 3