I essay the task more as a _jeu d’esprit_ than for any result of economic value, by means of the _Mugil capito_. This grey mullet has been identified with the ancient _’Ad_, a fish which figures frequently in the representations, _e.g._ in the Tomb of Ti, of Ptahhetep,[867] and of Naqada.[868] Its habit of ascending the Nile from the sea was known and noted by ancient authorities. Strabo, after stating that it, the Dolphin, and the Shad were the only fish so to do, informs us that the Mullet in his upward journey carefully consorted with the Schalls, or Catfish, whose strong spikes afforded it protection against the crocodiles.[869] We find at the end of the XXth Dynasty, say 1200 B.C., that 300 of _Ireth_ fish, 100 of _Shena’_, and 800 _’Ad_ (each lot) fetched 1 _kite_ of silver—the _kite_ being 1/10 of a _deben_ of 91 _grammes_. Although in the XVIIIth Dynasty gold had been just twice as valuable as silver, at this time silver stood to gold in a ratio of 1⅔ to 1. Thus 100 _Shena’_, 300 _Ireth_ (both of which are as yet unidentified) and 800 _’Ad_ fish were (each lot) worth 91/10 × ⅗, _i.e._ 5·46 _grammes_ of gold. Now one sovereign weighs 123·27447 grains, and as 11/12 of this is gold it contains 113·0016 grains of gold. As a _gramme_ equals 15·432 grains, the value of 5·46 _grammes_ of gold thus works out at about 14 shillings and 11 pence to the nearest farthing. The whole calculation, however, depends on the assumption that the _kite_ is known to be exactly 9·1 _grammes_. This, the latest estimate of its probable weight, can only be an estimate, for the Egyptians of the XVIIIth Dynasty, at any rate, did not make weights to a minute fraction of a _gramme_. A calculation therefore to the nearest farthing is somewhat meaningless, unless the weight of the _kite_ is determined to be 9·10, and not 9·09 or 9·11 _grammes_. Since the weight is certainly not known to two places of decimals, it is doubtful if it can be regarded as correct to the first place. Hence 14_s._ 11_d._ is not absolutely a more accurate estimate than 15/-.[870] Assuming for convenience that the _kite_ was worth 15/-, we could have purchased at the end of the XXth Dynasty 800 _’Ad_ fish for this sum. One fish would thus cost (15 × 12)/800 = 9/40 of a penny: but since the Egyptian _Mugil capito_, as sold in the big markets, averages (I am informed) ½ lb., the conclusion of the whole matter is that in the era mentioned 1 lb., or two fish, cost 9/20, or ·45 of a penny. In pre-war days the average marketable price worked out at 2·954 pence per lb., so the Egyptian _Mugil_ in 1913 cost about 6½ times more than _c._ 1200 B.C., while the English _Mugil_ in 1913, which (according to figures kindly furnished me by the Fishmongers Company) averaged 10 to 12 pence per lb., cost about 24 times more.