Dear Travis,

thank you for your image, essentially this is a matter of qualifying the
artifact, so first, it is in my opinion related to a latching mechanism - I
am cannot be certain it's not lamp related since we have examples of
hardware components being used across products - think of the old Henry
Ford story where the engines had to come in a specially designed wooden
crate - any damaged crates would result in the engine being refused by
Ford, and if you disassemble the crate carefully you have pre-cut floor
boards - so i'm not too quick to discount the potential that a plant may
have cranked out door hardware and some form of lamp hardware/chassis -

- the small bore on the shaft is for a set screw, which is usually a
slotted type - meaning a slotted screw driver - for a quick image
google*socket set screw
* for a modern version.  The knob itself receives a threaded spindle wich
can be a split spindle type - so picture a 5/16" piece of key stock, spin
it on a lathe to thread it and then slice it lengthwise p now take one
piece and cut it about 1/2" shorter, now take the piece not shortened and
hammer the "excess" 1/2 into a tight curve in the direction of the threads
- so what you do is take the longer half spindle and insert into the lock,
like a hook, where the curved piece goes in first through the lock cam -
think of a brass bushing with a 1/2 square hole - and with the hook set -
one has the split spindle piece sticking out of the lock, now slide the
remaining piece into the cam hole giving you a composite spindle sticking
out of the lock chassis and held in place by the hooked end initially and
synched by the filling of the cam hole.  now spin the threaded knob on with
"knob washers" first - picture taking a piece of tin you could fit a
cigarette through, about the thickness of an old school tin can wall, can
be shaped by a ball peen hammer, and after the knob is snug, you back it
off one full turn and then until the set screw can be installed against a
flat surface of the spindle - preferred to be not on the sides that are
split.

your piece is interesting since it is hollow and the knob itself is
wrought, then spun,  with pressure fit, so early machining, might be easier
to source than one might think - what's interesting is the overall diameter
-  i think it looks more like a screen door lock than a house door lock -
other attributes would be the centerline, if there is evidence of a
jappaned finish, and the screw pitches of the spindle and the set screw,
It looks pretty typical.  the tear is interesting since the metal, although
spun, is thick enough to break before peeling, so i'm wondering if this
knob has had significant wear - since these knobs in my experience tend to
dent or dent and pop the seam, i've never seen one "torn" - might be from
the excavation?  It seems an early date for the knob personally, but i'm
sure it can be sourced given enough time.  patent office would be one place
to find if the mounting portion(interior) is recorded.

It's curious that it is not a cast knob, considering marine usage.  again,
all is my opinion so i apologize in advance if there's an oversight -

Best wishes,

kev

On Mon, Nov 26, 2012 at 7:15 PM, Travis Shinabarger <[log in to unmask]>wrote:

> Hi all,
>
> I'm brand new to this listserv. I'm an archaeologist in Alaska researching
> a shipwreck. The ship was constructed in San Francisco in 1888 and went
> down up north in 1910.  We found one piece of brass likely associated with
> the wreck. I was wondering if anyone had any idea on how to research either
> door knobs or gas lamp fixtures, which, as of now are my best guesses as to
> what the piece might be. Links to catalogs or whatever might be seen as
> appropriate would be much appreciated.
>
> Many thanks,
>
> -Travis Shinabarger
>



-- 
kevin m. donaghy
graduate student
Temple University
Department of Anthropology