[Timo Nieminen]

Again, the problem with replicas and modelling is accuracy of the original thicknesses. If those are wrong, the draw weights obtained will be wrong. If the estimates of the original thicknesses are correct, there should be no problem. Since there are low estimates of the draw weights as well as high estimates, perhaps there is a problem. I will try to track down the details of the low estimates and see if I can see where the difference comes from.

Concerning Chinese archery and draw weights, we have some real data on what the common soldiers could manage:

"A 1736 report found that of 3,200 troops at the Hangzhou garrison about 2,200 were able to draw bows of strengths six to ten [80-133 pounds], and 80 could handle bow strengths of eleven to thirteen [147-173 pounds]… …In comparison, the 500 troops at the small Dezhou garrison acquitted themselves with honor, all of them being able to take a five-strength bow [67 pounds], 203 a six-strength [80 pounds], 137 a seven ­strength [93 pounds], and 85 a ten-strength bow [133 pounds]."
- M. Elliott, "The Manchu Way", as quoted on http://www.manchuarchery.org/bows

Note that only a minority could manage bows over 130lbs. Almost certainly, peacetime neglect of training contributes to this rather poor performance.

The Chinese military exams were for selection of officer candidates. The tests aren't meant to be something that every soldier can do; success in the exams is meant to show that the candidate is superior. The 70-75kg draw weights are for shooting on foot; the tests of horseback archery in the exams specify lower draw weights (usually 45-50kg). Then we have exams where lower draw weights could be used, to obtain an inferior pass (such as the Qing exams, where a 48kg bow was sufficient for the minimum pass, but 72kg was required for the top grade on this test).

Plenty of Chinese archers could shoot very high draw weight bows, 180lbs and up. It doesn't look like the majority of their soldiers could get close to that.

[Benjamin H. Abbott]

Note that according to Elliott the northern garrisons that saw combat more frequently likely had many more who could draw heavy bows and use them well on horseback. Also, eighteenth-century China was somewhat different from seventeenth-century China, and even more so from fifteenth- and sixteenth-century Western Europe.

Earlier, according to T'ien-Kung K'ai-Wu, the average [presumably infantry] archer drew 127-143lbs [80-90% of 120 catties]. Strong archers drew 159lbs, and the text specifies that strong archer were crucial to have on the battlefield to pierce enemy protective gear. It's not unreasonable to think English archers in general were strong archers during their heyday, much less that Henry VIII had mostly strong archers aboard the Mary Rose.

Again, European archers need the high draw weights given the relatively low efficiency of yew bows. According to current numbers on Manchu bows - which are shaky - a 100lb Qing bow might match a 150lb Mary Rose bow when shooting heavy arrows.

Finally, and don't know if we should give this any weight, some folks claims it's easier to draw heavy yew bows than heavy composites, especially Manchu bows. The difference in force curves supports this notion. I'm a little skeptical, though, given the reported high end on Qing draw weights.

[Will S]

I was gonna mention that difference but wasn't sure how to word it.

A short recurve is much harder to draw than an 80" longbow, there's no doubt. Anybody who could shoot a 150# recurve would have no trouble with a longbow of the same weight. Even just taking the string angle into account shows how much more uncomfortable it would be.

That's why it was so interesting to see a video of Joe Gibbs shooting a 177lb short recurve bow last year. That's more impressive than drawing a long self yew with the same weight.

[Benjamin H. Abbott]

Many folks say the same thing. I wonder exactly how it works. The high end of Manchu draw weights complicates things. An eighteenth-century Qing archer supposedly won a contest with an eighteenth-strength bow, which comes out to nearly 240lbs. The Kangxi Emperor claimed he could shoot a fifteen-strength bow in his youth (around 200lbs). And officers commonly tested with 160+lb bows even in the late nineteenth century. (They also lifted stones weighing nearly 400lbs and performed some sort of drill with 158lb polearm!) So if Manchu bows are significantly harder to draw, those numbers become even more impressive. On the other hand, higher draw weights for yew longbows would narrow the performance difference between yew bows and composites.

[Timo Nieminen]

While the force needed to draw a typical composite bow early is higher early in the draw, I don't find that this is where it's hard to draw the bow. At the end of the draw, what's the difference? Force needed is the same; the only difference is the string angle (for short recurves - a Manchu bow isn't a short recurve; it's a long recurve). I don't have any problems with string pinch drawing a 50" recurve to 35", but that's using a thumb ring.

I haven't drawn a strongly reflexed recurve-reflex bow (i.e., very C-shaped), only modern-style less reflexed bows where the force-draw curves are flatter. Such a bow will make the initial part of the draw harder. Looking at video of people shooting longbows (mostly only about 100lb or so), many archers just hold the bow up and pull the string back. A Manchu bow might be rather difficult with this technique. But if you learn to shoot a longbow in the Chinese/Japanese/Korean style, there should be no trouble with a strongly reflexed composite of the same draw length and draw weight. (What's correct longbow technique? While many draw by just pulling straing back, as noted above, others lift the bow and string hand a bit, and drop into the full draw position, like an abbreviated version of the CJK technique.)

If the draw lengths are different, there might be problems swapping between the bows. Drawing a heavy long-draw composite, your hand doesn't go that close to the full draw position with a shorter draw length longbow (or recurve), so the draw will need to be different. And if the rear elbow ends up too forward, that's just difficult.

[Benjamin H. Abbott]

Sorry, I was getting the text's title and author mixed up. It's T'ien-Kung K'ai-Wu by Sung Ying-Hsing (or Yingxing Song, depending on transliteration scheme). It appears in English as Chinese Technology in the Seventeenth Century. I've read the 1966 translation by E-tu Zen Sun and Shiou-chuan Sun.

[Timo Nieminen]

The relevant Chinese text is:
凡造弓， 視人力強弱為輕重， 上力挽一百二十斤， 過此則為虎力， 亦不數出， 中力減十之二三， 下力及其半， 彀滿之時皆能中的
(from http://www.chinapage.com/science/tiangongkaiwu/tiangongkaiwu.html )
which I would translate (with electronic help) as:
Bows are made, with various draw weights for individual strength, draw weights of 120 jin/catty (72kg/158lb), beyond this is for tiger strength, the few in number, of force 20-30% lower (50-57kg/110-126lb)), lower strength, and half (36kg/79lb), good enough for all.

So:
Bows are made with various draw weights to suit individual archers. Bows of above 120 jin (70kg/160lb) are for the few who are exceptionally strong, while bows of 20-30% lower force (50-57kg/110-125lb) are for those of lower strength, and half-strength bows (36kg/80lb) can be used by all archers. [Implicitly, 120 jin is a strong bow, but not super-strong.]

(Is the 20-30% here wrong? Are there different versions that say 10-20%?)

[Benjamin H. Abbott]

You glossed it as "10-20% lower" back in 2011. The 1966 translation is somewhat different from what you did just now, which isn't surprising given how translation goes. (Unfortunately, I don't read Chinese.) I'll have to look at the 1966 translation again to check the percentages. I think it was 10-20% lower in that translation, but it's been a while. But that translation may have gotten it wrong. Does the Chinese text have a passage about needing 120-jin bows on the battlefield to penetrate shields and other defenses?

Update - Here's the passage according to the E-tu Zen Sun and Shiou-Chuan Sun translation, Pennsylvania State University Press 1966 edition, page 263:

[Timo Nieminen]

That 10-20% is the 1966 translation. "Out of 10, 2-3 lower" is pretty clear, which is why I wonder whether the translation is of a different version.

The following sentence is
但戰陣之上洞胸徹札， 功必歸于挽強者， 而下力倘能穿楊貫虱， 則以巧勝也。,
In battle array tearing chests and piercing [letters ???] requires strong pull, but lower strength (50-57kg/110-126lb) can pierce polar and annoy [?? "poplar pierce louse"], and achieve victory through skill.

It's clear (and expected) that high draw weights are valued for anti-armour performance. Since this is a 17th century source, the battlefields had plenty of firearms, but the bow is still expected (or hoped, at least) to do useful anti-armour work. (One could say that the Ming army was a cannon army, rather than a musket army like the Qing army, so firearms hadn't replaced bows yet. However, the Qing still expected anti-armour performance from bows.)

[Benjamin H. Abbott]

There are different versions. The link you're using is apparently to the 1959 reprinting of the original (1637) Ming version. The translators in the 1966 English edition aren't completely clear which version they're using, though it seems to be the 1637 one. In any case it's not a huge difference.

[Dan Howard]

[Timo Nieminen]

The 1966 translation reads it as "bows of 120 catty are strong, above that are for the very strong". The original text appears to literally say that "draw weights beyond 120 jin/catty are for the very strong", not "draw weights of 120 jin/catty and above are for the very strong", so looks OK to assume that the "very strong" doesn't include the 120 jin bows. Since they're not "very strong" or of "lower strength", so fair to call them "strong".