It all gets back to how these were used Doug. Remember all cash were stored on, and mainly traded hands by, strings. Strings anywhere from 100 to 1000 cash were standard payment methods. Also remember cash varied by weight frequently over time, with the lowest acceptable weight and anything heavier all counting as one cash. So against that backdrop, splitting coons in half like the Romans would not work, since they had to be able to be strung. Also, a simple retariffing also would not work. So, this is the only possible solution to retariff cash coins.
I still do not get it. Sure all coins had to be on a string but a sting of 50 seems a lot easier than 100 halves.
They were almost always used in strings of 1000, called li. Don't think of this like halving a coin to get a smaller denomination, think of it like restriking a denarius into an antoninianus. You take one coin and make it two, doubling the value (at least on paper).
Yes, or a closer analogy would be the Roman and byzantine practice in the provinces of cutting coins in half to make change. For cash coins that must be strung that is not an option, so this is the only way to do it.
i'll resurrect this year old thread to post a cash coin i picked up a couple weeks ago. Northern Song Dynasty, yuan you tong bao, seal script, 1087-1100 AD Emperor Zhe Zong, AE cash, 25 mm, 3.4 g, reverse blank. Hartill 16.261 the reverse is blank, and rough. it was stuck to another coin, when i got them apart...the other coin was in horrible shape, nothing to see. oh well, only 3 bucks.
picked up another one at a coin show a couple weeks ago. this one has been on "the list" for a while. Xin Dynasty, Emperor Wang Mang, 7 - 23 AD Da Quan Wu Shi (large 50 coin) 27mm, 4.7g Hartill 9.2