As the headline says I would like to know more about the history of Chinese currency, especially coins and the reason for the squared holes in some of them. I think later on (maybe about the Ming or Qing Dynasty) they did not all have holes anymore, but I’m not sure about which did and which did not.
I’ve also been told that Chinese used to carry around these kinds of coins on a string like on the picture of this website. Was this actually a common practice?
In this context I've also read the response to an older question on this subreddit. It basically says that the hole served to string them together, but was that actually the case or is it more the other way round? Like that this way of carrying coins was later adopted as it was more convenient. Kind of a chicken-egg problem.
Finally, today there are coins tied together as a symbol for luck and prosperity. Is it know when this tradition started?
Thank you in advance
There are, broadly speaking, two techniques for making coins. The first, which is the most common in the world today, and traditionally used in Europe and India, is striking. This involves taking a metal piece, known as a flan, placing it between one or two dies (hard metal stamps bearing images), and applying force with a hammer or, since the 16th century, a screw press. The second, which was used in East Asia but occasionally in the Mediterranean, is casting. Casting involves creating a mould, reusable or otherwise, into which molten metal is poured. Once the metal cools down, the mould is separated and the coins removed.
Both techniques have their advantages and drawbacks. Striking traditionally required more human labour, while casting was less energy-efficient, because the metal needed to be melted down rather than simply heated (and indeed whether Greek and Roman coins were even heated at all before striking has been debated). Casting also is less efficient with material, as you need to produce channels in the mould for the molten metal to run down, which will also be filled by metal – these channels, and the cooled metal that ends up in them, are known as sprues. In addition, moulds always have thin gaps in them which some molten metal will escape into, leading to some material protruding from the seam where the halves of the mould meet, known as flash, which in the case of metal can be sharp and make the cast objects unpleasant to handle without further finishing. As such, the edges of cast coins need to be filed down in order to remove this flash. (Put a pin in that last part.)
The end results are also different. Before screw presses and milling, casting could produce much more consistent quality than striking, but the quality of the images was much better on struck coins for metallurgical reasons that I won't get into here. One extra feature of cast coins (pre-screw presses) is that they can be made in somewhat unusual shapes, such as to have a hole in the middle. And here's where we go back to the pin. The square hole could be used to fit an axle which could be fitted to a lathe, so that the rough edges of the coins could be smoothed down in bulk.
As for the strings, while I'm not sure about when those came into use, certainly by the Qing period it was quite standard practice, owing to the relatively low value of individual copper coins. A standard 'string' 串 chuan was about 1000 coins, give or take, but for more everyday purposes a 'hang' 吊 diao of ~100 was more common. Even so, if you were going out for a meal you probably wouldn't even need that. Bear in mind that prices rose over the course of the dynasty, but during the Kangxi reign (1661-1722) typical costs were 10 coins for a bowl of noodles, 4 for a side dish and 2 for a pot of tea. I don't know if David Hartill is using 'strings' as a shorthand for '1000', but it's possible mints assessed their output in 'strings' as well.
As for their being tied together for use as charms, that's an area where I don't know the origins, but certainly it was in use by the Qing period.
Source:
David Hartill, Qing Cash (Royal Numismatic Society Special Publication No. 37) (2003)
EDIT: I forgot to address one little bit near the start of the question. During the final years of the Qing, milled coinage was introduced, of which some retained the square hole as a design feature, while others were solid. An example of milled cash can be found on the right side of this image, while from 1906 onward a new series of milled denominations was introduced, with the smallest denomination retaining the hole, but those from 5-cash upwards not having the hole. (Images from Wikimedia, submitted by Scott Semans.)
Can I piggie back this? I remember reading somewhere that the holes were for spiritual reasons as well? Something about spirits being able to pass through them/good luck kind of thing? Is this true or a misconception?
