The use of crossbow sights is a much debated topic in the SCA. It is well
established that there WERE sights on crossbows, but exactly what forms they
took and when is the contention.
Payne-Galweh's figure 115 of a bullet ccrossbow from the late 1600's shows
well developed adjustable sights, both front and rear. The use of these
sights this late in time is generally agreed upon. The question remains,
what were the precursers of these sights and when were they used?
Part of the answer to the question left open by Payne-Galweh is substantially
narrowed down by W F Paterson with his Figure 24 of a Belgian crossbow from
the 16th century (100 years earlier) which displays a rear sight in a
dovetail of some sort. Unfortunately, Paterson's text refers to 17th C
bows when he states that his research in this area showed "Rear and
foresights became *MORE* elaborate...." indicating that they had already been
there before this period. He states,"....targets were very small and
precision sights were needed."
Harmuth's Die Armbrust seems to be silent on the topic as near as my poor
German (a remnant from college days) can decipher.
I can add that from my own personal observation of bows in several museums,
many from 1500 onward have some form of socket or hole behind the nut or
release which appears to have been a place to affix a detachable rear sight
mechansim. I can think of no other reason to put a hole in such pretty bows
in such a critical place!
Josef Alm's survey "European Crossbows" discusses the radical improvements
made to crossbows in the 1500's. Figure 40 shows a German bow from 1600 with
an impressive adjustable rear sight worthy of a modern target bow. In his
text discussing crossbow development in the 1500's he states, "In addition,
these crossbows have sights, usually peep-sights, and these were often of
very complicated design. Like the lower part of the trigger, the sight could
be hinged forward so as to not be in the way while spanning." (which
explains the socket holes I mentioned above)
I hope this helps some.
Master Ailean Mac an Daroch