It's not a translation, it's written in English by an Englishman who had visited Constantinople and I'm sure had seen one in action and wasn't just regurgitating orientalist stereotypes. He spells it yatagan or yataghan in different places, and it's a manuscript from a private collection so it's never been published and I guess it beats that 1819 reference by a few hundred years. I'm positive it was written between 1590 and 1600, the author was dead by 1620.
so they were shorter and more knife-like than sword-like around 1600? were they known for being hard to defend against for any particular reason? were they curvier, more S-shaped? the context is basically that getting into an argument with this guy is like being attacked with a yatagan. it could just be as simple as "he's sharp and nasty" but I feel like there's something more specific about his style of argumentation being implied.
Sorry for the delay. I just finished looking over the ones on display and reviewing the database of the non-display ones. Prominent features: 1) single-edged double recurve, 2) Older ones are 18-ish inches; newer ones go up to 24 inches. Still very short, considering. 3) All had a strong distal taper starting at around the midway point of the blade. Thicknesses by the guard were as high as 1/4" and as low as 5/32", tapers are to about 1/8". 4) Older versions have a smaller knob at the pommel, later versions highly accentuate the pommel into a broad winged shape. Later versions we have (ie 1802-1822) are clearly more ornamental with these wings but all our yatagans have something to stop the hand from slipping out during swings. 5) Association with courts, higher-end retainers, and higher-quality troops, probably cavalry, start very early in the 16th century Ottoman near east. Overtime this becomes a more commonly seen weapon, and therefore the more exagerated its defining features become, as the Ottoman influence expands into the balkans.
So what to make of all these facts. I am thinking that this is a thin, fast, sharp, and very nasty weapon for anyone not sufficiently armored. The pommel is going to secure your hand during the very fast swings you will be doing--fast because the blade is so short and light. It's sharp because of the distal taper, thin grind, and recurve that will all concentrate your high speed into as thin an edge as possible. In terms of fighting, we're talking about a very scary sidearm for the sorts of undefended people encountering these around the better-off men who would carry them. On a battlefield there would be numerous more deadly weapons with longer reach--pikes, ranged weapons, guns, that sort of thing. But in a more settled area like I am thinking it is not so different from an edo-era samurai carrying a katana. You could actually carry this around a city. It's not very large. Even not being very large, it's going to be a larger and more dedicated weapon than anyone else is going to have. So there's some interplay here between where it's likely to show up, ie a court, a city, a sidearm on cavalry, and it's actualy killing power.
The speed thing and the recurve is interesting. I do not know how one would fight with this except to say that the pommel design is obviously for cutting. One thing I can tell you for certain is that a recurve is going to appear a bit strange to a defender because the striking tip is slightly ahead of the body of the blade. You could feasibly rotate to turn the blade to hit slightly differently on the wrist than it looks like it might (during a parry, the blade will slide down and the recurve will bite past the defending guard onto the wrist) but I wouldn't go so far as to so this is likely because the recurve is not so pronounced that it's an obvious strategy. So I don't know. It's probably more about the elite who would have this weapon and the training they would have vs the more common people and soldiers. One thing that is up in the air for me is the role of thrusting. The handles are quite straight, which is interesting because that allows for easier thrusting, as does the recurve. Modern fencers put a curve in their blades to facilitate the sort of dropping in shot that comes with turning the point towards a target during a lunge. But are these stabbers? They might be, because they are short and that makes stabbing quite a bit easier. But they seem to be primarily for slashing because of the pommel design.
These are just my random thoughts. As I said, I am no expert. I took pictures of the two we had on display, which, lucikily, included what I think is the most wonderful and oldest example we have. I will post them later.