This cabinet has me stymied. First I thought card catalog, but the labels on the drawers have numbers not letters, which would be an odd choice. Then I thought a postal cabinet for a general store, and maybe the numbers were the blocks or something. But the real kicker is that weird shade on the top. That thing just makes no sense to me at all.
It’s obviously highly customized for a very specific purpose. But what on Earth would it be used for?
That’s not a shade on top, it’s a place to view open files. Note the lip on the bottom ledge.
Its a custom bookkeeping cabinet. Special ordered to meet a specific business’s system needs. Unless you knew the specific business it would only be speculation in regards to its application. Even then you would need personalized training to use it.
(I have no knowledge in this field.)
My guess would be that this was used in a bank or an insurance company. The small drawers had cards for individual customers or cases. The larger drawers had index books allowing an employee to look up customer numbers.
They don’t seem to have included pictures of the top, but I can easily see using the angled top to open a ledger or one of the index books, and the “shade” part would have contained an electric light.
Second guess, to explain the vertical slots and the ruler: a land registry office, or a firm of surveyors. Store maps or plans in the vertical slots, use the top to view them, use the ruler to help with scaling, and the drawers contain ownership information.
I initially thought the things on to was to hold a light, and protect your eyes from direct glare, so you could read the item you placed on the cabinet. But looking at the lip, i agree with @Si_Amigo that it’s probably just a surface for holding (and reading) ledgers.
It does like like it contains both cards and larger materials, as @Heracles suggests. I can see it being useful for an insurance agent, who needs to keep a card for each customer, books of insurance plans and schedules, and some general files for the office, as well.
My guess would be some kind of apothecary: the drawers hold tinctures, pills and tonics 
while the slotted area holds customer/patient files which can be laid out on the flat part while prescriptions are being filled.
If Phoebe finds out that’s really from Pottery Barn, all hell will break loose.
That thing is listed as 56 1/2 inches tall. Maybe that’s a reasonable reading height for something?
Lots of potential storage uses in, say, a vintage hardware store.
It could have been used in the garden department for storing seeds.
If you blow up the image of what has been referred to as a ‘ruler’ it reads: Turtles, Standard Gauge, New York, I.T.U. Card, 5419. Google tells me that was a gauge used by printers and typesetters to measure picas and points. So the cabinet likely was in a print shop, though I have no idea of what they might have stored in the cabinet.
Yeah. Letterpress and typesetting furnishings seem to have been a specialty of Hamilton Mfg.
There are 6 picas to an inch, and 72 picas (the length of the gauge) would be 12 inches, so it definitely looks like picas, and too rough to measure points. And it’s fixed, so you would have to hold something up to it in order to measure it.
What I don’t get are those slots in the front. They appear to be only about 3 inches deep, and 10 to 12 inches high. I’m having trouble imagining what those would be useful for. Temporary sorting, I suppose, but what kind of thing would be that tall and narrow that would fit in there and not fall out? Card stock, maybe, but for a very specific size and purpose. I tried to count the number of slots, it looks like 32 across, including those where the dividers are missing.
Individual letters to be typeset?
Hamilton made cabinets for printing offices. Here is a catalog from 1905:
http://www.telephonearchive.com/dmworkshop/assets/pdfs/hamilton_1905_catalog.pdf
My guess too. They called them “Type Cabinet” on page 44, for instance.
As a long time collector/horder of Letterpress printing and type setting equipment, an immediate thing that comes to mind that would fit in those slots is leading. Many of you might be familiar with the term leading as being the setting that tells you how far apart lines of text are. Well it used to be done in the good old days with strips of lead of various thicknesses. Generally came in a long strip that you cut to the needed size. Those could fit neatly there.
In terms of the little drawers, the only immediate speculation I have is the drawers could be used for logo cuts, and other pictorial bits of type. Normally, most of the stuff you’d use to set type would fit in the job case which looks nothing like what these drawers are. But there was always a need for bits of imagery, like flags or banners or company logos, or illustrations of people, whatever, and those needed some sort of sorting and filing system. You wouldn’t have a jillion of them like you might have individual letters of a type face so a small drawer per category might work.
Also, from the description, the word turtle in the typesetting world indicates a heavy, rolling surface for moving locked up forms of type from the composing room to the press.
edit: no - in this case Turtle’s refers to the brand of type gauge nailed onto the cabinet. That gauge is not finely ruled enough to measure different type heights, which reinforces my belief that it’s the thickness of the strip material stored in the slots below because that sometimes comes in less granular increments.
Individual letters would always have been stored in a job case. You would go mad setting type by running from tiny drawer to tiny drawer to grab the correct characters in order
Leading makes more sense to me than letters. The cabinet on page 44 of the catalog linked to is a cabinet of shallow trays (or job cases, as noted above), each full of letters of a particular font (typeface and size), which the setter could pull out and use at their work station.
So I can see 32 different sizes of leading slugs being needed, which would work for any font.
See page 56 of the catalog: there is something there the called “electrotypes” that look like logos. But they seem not to be cut but perhaps electroplated?
The drawers could be customized and the little boxes (bigger for the letter e, smaller for the x) were movable (page 49).
I can imagine collecting things like that if you have the space. And the money, they seem to be expensive.
Now let me browse that catalog a while longer.
Yes, what are called cuts in the Letterpress printing world were originally engraved, and were later electrochemically etched by different methods. Sometimes in magnesium sometimes copper.
Page 52 of the catalog posted above has the closest match to what we’ve got here. That item description calls out the small drawers, as sort drawers for the use I mentioned above, storage of small cuts and pictographic things that don’t fit within a font of type. I suspect the dual tier arrangement on top is to hold the uppercase in the elevated part and the lowercase on the top of the cabinet. When setting type, you would pull the whole drawer out out of the storage cabinet and set it up so that you could grab type with one hand and put it in your composing stick in the other.
I find the skewed, slanted drawers great. They were made on purpose that way so that the letter types and the “delicate borders” did not rub against each other, but stayed on one side of the boxes. See page 61.
Those cabines were made for people who worked carefully and appreciated order.