Persian horn strip construction

There is a picture of a dissected Persian bow in "On the Structure and Affinities of the Composite Bow" in The Journal of the Anthropological Institute of Great Britain and Ireland, Vol. 19(1890), pp. 220-250 by Henry Balfour. Incidentally the horn strips are on the belly not the back.

Edward McEwen made several of these bows. I have handled one of his reproductions and two originals. The horn strips were put on one by one according to McEwen. He told me that it was easier to assemble a bow with strips because they were more individually flexible, but it took much longer to assemble the core and belly than on a Turkish bow for instance.

The bending sections of the limbs are wider than in a Turkish or a Crimean Tatar bow. The horn belly is completely covered in sinew and whatever is used to cover the sinew (bark or leather). This means it is difficult without dissection or the use of CT scanning to tell how many strips are used. The Persian texts that Dr Khorasani translated and asked me to study suggest generally even numbers of strips. Four and six are commonly mentioned.

Bows in museums are often flattened out and exhibit extreme string follow, but this is usually because they have been strung for years (maybe centuries in some cases). Some bows in the museums in Iran from the sixteenth century show that normally they retain a great degree of their original reflex. This is not surprising since they have wide thin limbs.

The bow that Balfour dissected had an applied handle glued to the back of the core like a Chinese bow. I have not found many references to other dissected bows from Iran, but I think that a separate spliced in handle is likely in some bows. I base this on the fact that bows with related structures like the Sind bow and the crab bow do have separate handle pieces. The Sind bow does not have multiple horn strips, but does have similar ears to the Persian bow. The crab bow sometimes has multiple strips and shares the wide bending limbs.

There are some bows from the Northern Pakistan and also Afghanistan that have similar structures to the Persian bows.

that article and some more reading I did this evening has answered most of my questions. but I have a few more. first off the fact that the Persians used multiple thin strips of horn, why did they do that. were the strips leftovers from making other bows or were they strips of a skinnier horn such as a Arabian Oryx horn. also why the transverse wrapping of sinew around the entire bow? it seems as though all Persian bows do this even if they were constructed of 1 piece of horn. is this needed for strength or...

afaik this is no transverse wrapping of the whole bow, but a longitudinal sinew cover or ?

I have been searching for Balfours article both in my "library" and on the net, but found only one source where it could be bought for 20$. Is this the only option? I thought I had read the article somewhere before...

For the crab bows it seems like the sinew on the belly was used as a "filler" to fill in and make the belly round when there was used a piece of horn that was considerable narrower than the wooden core. In a bow with several strips I would think a final sinew cover would help secure the fragile glue lines between the horn strips. On my last crab bow attempt, which has only been braced once yet, I found that lngitudinal laid sinew should be glued onto the belly with glue that is very flexible, to avoid compression marks in the sinew/glue. I used a mix of hideglue and cod-bladder-glue, which was not flexible enough. I am considering using rabbitskin-glue mixed with bladder glue for the next bow.

It's a very interesting topic. I have a core for a crab bow that I am considering trying to use several strips on in the near future. It would be good to put to use some scraps, and I'm sure the ancient bowyers felt the same if there was not a good surplus of avaliable horns.

I did find this page, with one of (?) the illustrations by Henry Balfour:

http://england.prm.ox.ac.uk/englishness ... apons.html

[external image]

The number of strips on the belly seemed to vary. One bow I examined had 5 strips and did not have any sinew on the belly of the sal section (only paint). The kasan section was wrapped transversely with sinew however. If i remember correctly another bow I saw a picture of (Manchester Univ.?) had 7 strips.

I made a couple of these bows, not exactly Persian style, with 3 strips - too much work. I have seen McEwen bow as well and I agree with his opinion. The strips were glued one by one, which is probably the only way to do it, since the strips are quite thin. I have a Persian core made up again, but hesitate to cut good horn into strips for the belly and plan on usins waste pieces perhaps. Ivar may be right about the sinew used to fill in the irregularities if needed.

The bows turned out to be a little more flexible than expected. I think the mutliple strips are less stiff (lower modulus) than one solid strip. It is indeed possible there was not enough wide horn at the location the bows were made.

Adam

first off for anyone interested here is the anthropological journal in its entirety. just click read ebook on the left side or you could download a pdf.
http://books.google.com/books/about/Jou ... YMAAAAIAAJ

also thinking about it yesterday and some more today, I would have to agree the the transverse sinew on the horn side of the bow was more of a filler to give the birch bark of leather a smooth base to be glued to. as it would have to be applied after the bow was tillered and probably shot a few times. I think I may try this on one of the bows I'm currently working on, but I have to agree with Adam I wont be cutting up good water buffalo horn for this. I think I may get a gemsbok horn, slice it up , and see how it goes.

heres a question though, Adam you mentioned that the time that you tried this the bow ended up more flexible than you expected. did this extra flexibility reduce the draw weight significantly? if so would you suggest increasing the thickness of the horn or sinew to make up for the loss?

also I'm still curious as to why they did this sort of construction, do we all agree that it was probably just to use up scrap materials? or could there possibly be some sort of advantage? with the amount of extra work involved there has to be a reason.

I would not try to make allowances for the lesser weight. The difference was small, prob. no more than 10%.

I have seen pictures of water buff. horns sold out of Pakistan at one time. The horns were not nearly as wide as the South Asian buff. and not as triangular, almost round. One could not cut a wide, flat strip (as wide as 5cm for a Persian bow) from such horn. Perhaps they had a similar problem.

Adam

Adam you do have a point about the horn, I have seen those before.

my only reason I was thinking about the oryx or gemsbok horn was the fact that the Persian empire eventually occupied part of Egypt and the Arabian peninsula. which both have gemsbok as native species, so my thought was that instead of shipping water buffalo horn across the continent by horse train (which could take months) that they would use something more local and cheaper. again this is entirely out of my head and i could be way wrong. just a thought I had.

Eelectroman wrote:

first off for anyone interested here is the anthropological journal in its entirety. just click read ebook on the left side or you could download a pdf.
http://books.google.com/books/about/Jou ... YMAAAAIAAJ

Thanks for the link, but apparently there are different regulations depending from which country you try to access this. "No ebook available" is what I get in Germany.

There seems to be some confusion about what horn was available in Iran. Buffalo horn was easily available in the times that the type of Persian bow we were discussing was made. Other even more exotic horns were used according to the old texts. Very wide limbs would have needed multiple strips no matter what animal was involved.

McEwen thought that the use of multiple strips was a way of maximising the number of bows that can be made from several pairs of horns. It's rare to find Persian bows with only two horn pieces. Multiple strips are usual. Some bows were made with no no sinew or even paint were made and were still functional. One is in the Grayson Collection. The benefit of the sinew wrapping, transverse or axial, is that it compresses the whole structure. A similar technique was used in Korean crossbow laths with wooden bellies.

The book, The Grey Goose Wing, has a series of cross sections of a crab bow with multiple strips of horn and much more wood in the ears than common. I think using the offcuts of other bows for the strips of horn for a Persian bow is a good idea.

Adam, McEwen also mentioned the increased flexibility. Persian bows were usually longer than Turkish as were the arrows.

Here is a pic from Pitt Rivers

It is at the middle.

so it would seem that we agree that the transverse wrapping of sinew is not required, but is there an advantage to it? does that extra compression hold the laminations together better? or does it help with stability?

Heavy Korean cross bow laths had transverse wrapping. Since they were usually bamboo cored and wooden bellied, it suggests that they thought that the belly would be supported by the compression. These bows are short, reflexed into a circle almost and very thick.

I know of only one person who has tried making one of these bows, but I have not heard the result.

I am not engineer but

wouldn't a wrapping counteract the poisson effect and thereby
increase tension ?

otherwise, as long as the cross-section is increased by sinew
we have the double effect of cubic increase of drawweight with diameter
plus stabilization by tension backing (if the sinew is wrapped spirally)

?

With regards to how long the narrow strips should be, and where they should end: Is it okay to let some of the horn strips on the sides of the limbs fade out in the middle of the bending part? These bows all have bending parts of the limbs that more or less have a width-profile that is widest at the middle and narrowing in towards the grip and siyahs/kasans. To be able to fill up all of the width in the limb, I guess there would have to be some short horn strips along the edges, that would not be secured at the ends by the non-bending grip and kasan/siyah? Is this a problem?

Or maybe the width of the strips should be adjusted so that all of them travel from grip to kasan/siyah?

As general information, the terminology for bows in Persian.
Ear گوشه gu?e This is the equivalent of the Arabic siyah, Turkish kasan and baş.
Limb of Bow خانه xāne This is the equivalent of the Arabic bayt, Turkish sal.
Limb of Bow دستار dustār This is another term for the same thing. It also entered Arabic.
Grip قبضه qabze This is the Arabic qabḍa.
Arrow pass ديمك dīmak or daymak This word also went into Arabic and Turkish.

I am not sure of the profile of all the strips. It would be relatively easy to arrange for the end fade outs to be near the neck (transition from the bending arm to the ridged section) and the grip. Since the whole limb is in compression because of the sinew, the forces generated while bending the bow should not cause the strips to lift off.