rabo e pião de canhão

14:47 May 25, 2014 

I also cannot find any other solution in PT>EN that would make more sense, so "vent pick" it is. Once again, thank you so very much for your collegial help that has allowed me to finally wrap up this arcane and archaic technical translation.

10:09 May 25, 2014 

As far as I can see, the only logical explanation is the "pick", however I have found no evidence in Pt. Regarding the object, the metaphor of the "vent" as a keyhole, and the "pick" as a chave would seem to lead in the right direction.

08:34 May 25, 2014 

Once you suggested "lantern" and "ladle," I google'd them with other keywords and found the most references with illustrations of "ladles" for Renaissance artillery. The ladles indeed scooped up powder and poured it into the cannon, followed by the ram-rod to pack down the powder. Thank you!

The last term I've been struggling with (the whole list has taken me weeks, these were the final ones I couldn't figure out) is "chave." Chasing down hints from your links, with a healthy dose of [educated?] guesswork, I suspect it refers to the "vent pick" (also called "gunner's pick") that was inserted into the vent to clear it out and/or piece a bag of powder so the flame from the primer could ignite it. In the images I found, many vent picks look very similar to the "chaves" we now call screwdrivers. The common thread in the various kinds of "chaves" seems to be a tool that is inserted into something, in this case, the vent. Does this make sense to you?

08:10 May 25, 2014 

I thought about this and my fist choice would have been a type of "shovel" to load the powder but i couldnt find the references.
However, this may be useful:
The lantern or ladle serves to carry the powder into the piece. It consists of a wooden box appropriated to the caliber of the piece for which it is intended with a length of a caliber and a half with its vent, and of a piece of copper nailed to the box at the height of a half caliber. This lantern must have three calibers and a half in length, and two calibers in breadth, being rounded on the end to load the ordinary pieces
http://en.wikipedia.org/wiki/Cannon_operation#cite_note-EB17...

03:26 May 25, 2014 

Thanks so much, Nick! "Cascable and knob" make perfect sense, and the sources you so helpfully supplied confirm them. I can see why the knob is called a "pião" in Portuguese, given its similar shape. "Carriage" checks out, too. I like "ram-rod," but it probably better matches "atacador." Do you think "loader" might work for "carregador"?

20:10 May 24, 2014 

probably refers to "carriage"
carregador probably ram-rod
http://www.history.navy.mil/cannons/cannons55.html

19:57 May 24, 2014