Imperial diptych offerings to the emperor. However, the fact that the Barberini ivory was almost certainly not a diptych, but some kind of imperial icon without a second panel is a serious argument against the existence of the imperial diptych type. The two panels representing the empress Ariadne, in the Bargello in Florence and the Kunsthistorisches Museum in Vienna, also belong to the hypothesied imperial diptych type. They are the only central panels of such a diptych (other than the Barberini ivory) to survive, since all other fragments of such diptychs are from side panels. Imperial diptych In Late Antiquity, an imperial
Imperial and US customary measurement systems ounces (of 437.5 grains). The unit of volume, the gallon, has different values in the United States and in the United Kingdom – the US fluid gallon being about 0.83 imperial gallons and the US dry gallon being about 0.97 imperial gallons. Both systems of measure were widely used in mechanical engineering, though not in electrical engineering. Some units of measure such as the horsepower or the British thermal unit (BTU) have special names but by and large unit names are generated from their constituent components – for example, pounds per square inch. In contrast, the metric system has a