Jack with a Lantern

I did a little search for old images of Jack-o'-lanterns, which turned into a brief peak at their twisted history.

From Jack o'Lantern and Other Rhymes, 1883 (which features several jack-o'-lantern illustrations)

Halloween is an old holiday.  Viewed as a harvest festival it's extremely ancient.  But it's more modern form begins with an evening celebration before All Saints Day, a holiday of some branches of Christianity.  Also called All Hallow's Day, the evening before was All Hallow's Eve, eventually becoming Halloween.  Wikipedia says this name took hold by 1745, and I easily find it in several late 18th century sources.

By this time Halloween was already associated with supernatural activities, "witches, devils, and other mischief-making beings", especially fairies (from Robert Burns' footnote on his 1785 poem Halloween).  It was also associated with cabbage (also called "kail", and which might be the same thing in this context as turnips), which was apparently pulled up on Halloween as a way of predicting the size and shape of your future spouse (also in Burns' footnotes).  An 1897 source claims that cabbage may also be pelted against the door of a house if things get carried away, which certainly sounds like a "Trick" portion of "Trick or Treat".  This is somewhat verified by an article about Christmas and New Years celebrations in 1831 (The Edinburgh Literary Journal), which warns that if you don't reward "guizarders" (think Christmas carolers with clowns instead of singers), that you'd better keep an eye on your cabbage the following Halloween.

But probably just as old as Halloween, and possibly even older, are "Jack-o'-lanterns".  Except that they weren't pumpkins.  Depending on the source they were "fairies" or "spirits" or perhaps in more scientific contexts they were "meteors" (a general word in that era that included many unexplained glowing phenomena of the night).  Today you might have heard of "ball lightning" as a possibly related phenomenon.  The closest phrase you might have heard of these days would probably be "ghost light".

The demon version of the Jack-o'-lantern, from George Cruikshank's Omnibus, 1877.

There's a centuries old legend describing a light that's observed in the mist in swampy areas, which recedes away if the observer follows it, drawing them away from the path, sometimes to their doom.  Much like ball lightning, there's enough documentation on this phenomenon to wonder if it's more than just a legend.  And it has been scientifically investigated to varying degrees over time.  This phenomenon was called Ignis Fatuus (foolish light) in more academic sources dating back to at least the early 1600s.  Colloquially it has two popular names: Will of the wisp, and Jack of the Lantern (or sometimes Jack with the lantern), which are also at least that old.

Scientific investigations of the time blamed this effect on a few different things.  One possible source was the Aurora Borealis, however most descriptions generally seem to indicate that the light was close by.  One description claims that by holding still and averting their breath, an observer was able to use a Will-o-the-wisp to ignite a flame, and that where it occurred the ground could be set on fire.  This has led some to believe today that there is a very real "cold flame" chemical reaction involving methane and other swamp gases that created a light, which would recede because a person's breath and motions would disturb the delicate balance needed to preserve such a fragile chemical reaction.

In other words, blaming unexplainable phenomena on "swamp gas" dates back hundreds of years.

(Personally I can't help but wonder if the same refractive effects that cause Sun Dogs and Moon halos might under very specific circumstances of icy fog and moon position create an effect in fog that may appear very close, and yet appear to remain at a certain distance no matter where the observer moved.  Although given the "cold flame" descriptions from history, this would only explain a subset of these events.  It's easy to dismiss such descriptions as nonsense, but I like to remind myself that people who wrote those books were exactly the same human animals that I know today.)

From American Agriculturist, vol. 39, 1880

So why "Jack with a lantern"?  Why for that matter, "Will of the wisp"?   I had originally taken "Will of the wisp" to mean the fog had a will of its own, but apparently Will in this case means William, just as Jack is a name short for John (but often associated with mischief).  And some sources attribute "wisp" to a sort of simple torch made of bundled leaves and twigs, which makes it more of a parallel with the name "Jack of the lantern".

There's also a story of Stingy Jack that has been attributed as the origin.  There's a poem that I can find in 1851 about Stingy Jack and a deal he makes with the devil that keeps him out of hell.  Since he can't get into heaven either, he walks the earth, for some reason carrying a lantern.  However I find "Jack-o-lantern" seems to much predate Stingy Jack, so I'm inclined to think that Stingy Jack is a later bit of fun rather than an origin.  On the other hand, some similar lost tales may sit at the origin of both "Jack-o'-lantern" and "Will-o'-the-wisp".

Another source from 1834 claims that the real origin is the latin word "jaculantur", which has something to do with throwing spears.  In this alleged origin, nighttime spear-fishing was a popular sport at one time, and links the latin word with the person holding the lantern during this sport.  But as with Stingy Jack, I find no mention or hint of this in anything from the 1600s or 1700s.

At any rate, the name "Jack-o'-lantern" is apparently much older than the name "Halloween", easily appearing into the 1600s along with Will-o-the-wisp.  Some sources list it as Jack-o-lanthorn, where "lanthorn" is an alternate form for lantern which fell out of use in the 1700s.  It's often used as a euphemism for being led astray, even in the earliest sources I've found.

As the name of a ghost of fairy or spirit, the name "Jack-o-lantern" was naturally associated with Halloween as early as Halloween was associated with the supernatural.  But when was the name applied to the carved pumpkin?

From Harper's Weekly, 1867

Carving faces into vegetables is most likely the oldest aspect of this entire tradition.  Peruvian gourd carving is 3,500 years old according to many online sources, and I have no doubt that carving effigies into vegetables is substantially older than this.  More recently, Guy Fawkes night has in the past used painted or carved turnips for effigies of Guy Fawkes, generally burned and otherwise destroyed during the festivities, as noted (among several other sources) in the 1867 Harper's Weekly article that is the source of the above image.  It isn't clear if there was a candle in the turnip. However, many modern sources claim a close relationship in the practices of Guy Fawkes night (which is November 5th) and Halloween.

In another very old tradition, often attributed as a predecessor to pumpkin lanterns, the Scottish used to carve turnips into lamps and use them at Halloween.  According to an 1825 dictionary the entire turnip was carved thin enough to be translucent, and then the face was formed by "blacking" parts of the outside.  This was called a "Candle and Castock", where castock was a word that meant cabbage stalk or pith of a "colewort" (it's hard to track all this terminology since meaning seems to have shifted—cabbage, turnip, and "kail" seem to be used somewhat interchangeably).  At any rate, the same dictionary entry clearly establishes a connection to Halloween.  It would seem then that this would be a simple transition form turnips to pumpkins, but the history that I've found so far doesn't seem to confirm this at all.

Pumpkin lanterns seem to be fairly common in the U.S. through most of the 1800s.  It's important to remember that pumpkins (and other squash) seem to be an American plant.  Native Americans may have been doing this for thousands of years, but there's no direct record I know of that.  However the very earliest record I've found that combines pumpkins, lanterns, and faces, is from an 1832 story about native Americans in the New England Magazine, which describes a collection of "pumpkin lanterns, stuck upon poles, and carved into Indian faces with all sorts of inhuman distortions", and seems to tie them to the native culture.  Through the the rest of the 1800s, sources seem to indicate that carving a pumpkin and putting a candle in it was a boyish pastime, rather than a practical lamp design.  Most sources on pumpkin lanterns generally seem to assume that the pumpkin will be carved into a crude face as opposed to a plain lantern.  At least one source indicates that this was something done with useless, unripened pumpkins only.  Most of the sources indicate that it was often done as some sort of prank, used to attempt to scare children and the neighbors.

The earliest photo I've found so far, from Western Camera Notes, 1903

What's perplexing in all of this is that even though we have a turnip lamp with a face that's associated with Halloween by 1825, and pumpkin-face lamps existed around the same time, I can't connect pumpkin-lamps to Halloween from explicit sources until the 1890s (where sources are suddenly easy to find).  I can establish that pumpkin-face lanterns were called "Jack-o-lanterns" by 1855.  The Oxford English Dictionary traces it to an 1837 source, which is fairly convincing but still leaves room for confusion with the original meaning.  In fact, I've seen Jack-o'-lanterns or pumpkin lanterns mentioned in connection with Thanksgiving, Christmas (1876), and some sort of candle in a pumpkin for Easter (1845), before I see any connection to Halloween.

One thing I've learned about history is that you can't make strong assumptions about the culture based on books.  Today, our culture hits our media instantly.  But in the past "vulgar" culture was explicitly kept out of books.  Certainly this was tied to the expense of bookmaking, and the tendency decreased as the cost of making books steadily decreased.  In the 1600s and 1700s publishing was all about scholarly work.  In the 1800s, gradually more and more popular culture seeped into published works, as paper and presses became cheaper and higher quality, and printers proliferated.  And of course with the Linotype in 1886 and it's ability to produce about three or four times as much text at the same cost, popular culture overtook scholarly work.

So one might easily see the lack of an explicit reference as a simple oversight.  And yet I've read a few sources on Halloween customs that don't mention pumpkin lanterns at all, and a few sources on pumpkin lanterns that never mention Halloween at all.  This is hardly a rigorous analysis, but I tend to think that until the late 1800s, there was only a mild link between the two at best.

To summarize, based on my very brief examination, this is all I can confirm right now:

• Jack-o'-lantern, the ghost/phenomenon, by the 1600s
• Hallowe'en, by the 1700s
• Turnip-lamps with faces for Halloween, by the 1800s
• Pumpkin-lanterns with faces, by the 1830s
• Jack-o'-lantern as the name of pumpkin-faced lanterns, by the 1850s
• Jack-o'-lanterns for Halloween by the 1890s 

Britain on Hash

# part 2 

The "hash"?

In part one, we looked at the history of the number sign in the last few hundred years.  A brief overview of some very rough dates and usages (most of which probably happened a little or a lot earlier than what I've found):

1500s - musical sharp
1600s - proofreading symbol for space
1820s - Tic-Tac-Toe
1850s - number sign
1850s - pound sign
1960s - octothorpe.

But I left out the hash (or hash sign or even possibly hash mark) as a name and a usage.  This name is by far the most dominant name in England for #.  And after all the British created the English language, so they should know, right?

In a blog posting at oxforddictionaries.com about the name of the symbol, they claim that "the most common is probably hash."  I'm not sure who's posterior this "fact" was removed from, but lets hope it wasn't too painful.  It's certainly not the most common name in American English.  Perhaps they didn't realize the Internet extends outside of Britain.

Of course I'll readily accept that the British could never readily accept # as pound sign for weight, because that's already taken with their monetary unit, pounds sterling (£).  We'll just ignore the fact that the monetary unit comes from pounds of weight, which even the British have written as the symbol ℔ (which turned into the #) and which they'll read as "pounds".  Whatever.

Perhaps the real question is, what is the pedigree for "hash"?  Maybe the Brits really are right, maybe this is the true and genuine real name for this ancient symbol.

So I looked.

I've searched around in the 19th century, where I knew that "pound" and "number" were both well-established.  They certainly didn't use the word as a name for that symbol back then.  "Hash" was however a slang term for food, usually bad mass-produced food, sometimes a specific type of dish of meat and potatoes and other things all mixed together (i.e. bad mass-produced food).

In the 1910s and 1920s I find references for "hash mark" that referred to the military (or civil) navy marks on the sleeve used to indicate rank or experience.  We still call them that today.

Then, there it was, a reference to "hash mark" in 1920 that seemed like some other meaning entirely.  Granted it was still in a naval context.  But this usage was new.  Perhaps I was on the right track?

From The Log of the Columbia Naval Unit, 1920 (via googlebooks).

There it is!  A "hash mark" is also a synonym for a food stain.  That settles it.

At some point in the middle of the 20th century, Americans began referring to some of the markings on a football field as "hash marks".  That is to say, American football, not real (cough) football.  So yeah, we're not even going to explore this one as a possible origin.

In the 1960s I see hash tables appear in computer discussions.  And hashing algorithms.  This is a method of compactly storing and organizing random data in a semi-sorted and rapidly accessible form.  But as far as I can tell (and I'm a software engineer) there's never been any association between this method and the number sign.

Also in the 1960s, some old manuscripts from Mark Twain are published, including a story called "Three Thousand Years Among the Microbes", originally written sometime between 1896 and 1905.  In this story, a new monetary system is recommended, consisting of tenths of pennies called bashes.  A thousand bashes is one hash.  Of course, in the printing I've seen of this, no number sign is apparent.  Plus, Twain is American, so... no help here.

It isn't until the 1970s that I see the word "hash" used to refer to #.  A couple of things happened around this time.  One is that touch tone phones became popular, and incorporated the same keypad as in America, with this new and alien (to British) symbol.  The other is that "hash" became a popular nickname for hashish (which by the way is the origin of the word assassin).

Now don't get me wrong.  I'm not suggesting that these two new uses of the word "hash" that happened at the same time had anything to do with each other.  I'm just presenting the facts here.  But the mere possible suggestion is interesting, because of the vacuum it fills.  That vacuum is the void that is not filled by a true origin story for calling # a hash.

Several online sources claim that hash came from "hatch", as in the cross hatching artists use when drawing.  Except, the only place I find this is in these claims.  They cite no additional sources, and I have found no additional sources.  I've only seen this as a just-so story presented to fill that vacuum.

Honestly, if we're just going to make stuff up, I prefer the hashish theory.

OK, all the jest aside, I did actually find SOMETHING.  A google search in books for "hash sign" brought me to this:

Can you see that here?  I can't get to the full content.  It looks like two different printings of the same (or a similar) article.  One uses a number sign, the other uses something new:

From Research Review. Navorsingsoorsig, 1968-1971 as found in a Google search.

The source of this is from some sort of review of papers of that day.  According to Google it's a publication of the South African Council for Scientific and Industrial Research.  It seems to be a description of a Keyword-in-context (KWIC) index, or of some sort of method for marking up or automatically creating a KWIC index.

I have found many other references to KWIC software systems in that era, and I haven't found any others yet that mention a hash sign, or a number or pound sign.  Several mention a dash, and also mention it together with a slash.  "Slash-dashing" was used as a verb in a few.

What does all this mean?  I don't know yet.  This could be a printing error.  Or a symbol I'm not familiar with being imported in, and later substituted with a number sign.  It could be some combination of slash and dash, which ends up looking like an "H".  (Thus "hash"?  Oh man, do NOT quote me on that one, that is how just-so stories are created.)  But if we are making up just-so stories, it does strike me that this new symbol along with the original number sign are highly reminiscent of hash marks on the sleeve of a naval officer.

Until more information comes in, I'm convinced the British made something up off the top of their heads, to explain an alien symbol that appeared on their phones.  They couldn't call it a pound sign, because that was taken.  They couldn't call it a number sign, what with all the other phone buttons having actual numbers on them.  So they just hashed it out I guess.

So where does this leave us?

I set out to find the pedigree of "hash".  It has none.  It's a word with no long history.  In fact, at the moment it has no real history at all, since nobody knows where it came from.  Perhaps more to the point, it seems to be completely meaningless.

Compare this to "number sign", which dates back at least 160 years, and probably quite a bit more.  It's still widely used and recognized as a number sign today.  It means "number" in this usage.  So we have both history and semantics on the side of "number sign" (and of "pound sign" for that matter).

We can't defer all decisions to the British simply because that's where the language started (although not really).  And of course we have to acknowledge that language changes.  This is an inevitable process.  But that doesn't mean we can't have opinions on how it might best change or not change.  The ability to continue to understand past writers is a great one, worth preserving.  Meaningless and pointless changes to the language don't provide any benefit to anyone, and it doesn't matter if it's the British introducing these pointless changes.  If we are going to take the time to think about our language, we might as well encourage meaningful communication.

One thing is certain: we can no longer entrust the English language to the English.

The Sign of the Number

#

What is it?  How old is it?  Where did it come from?  And what should we call it?

The first time anything like this symbol appears in our history (as we've uncovered it so far) is one of the oldest known abstract marks made by any humanoid, in this case Neanderthals, about 39,000 years ago.

Neanderthal social media? (via Scientific American blog)

But that's a bit outside the focus of my blog, which is usually related to printing technology.  And so that's where we'll pick up this story.

Sharp

The sharp is probably the oldest use of this symbol, although it isn't very clear when it really began to look like #.  Originally the sharp symbol (as well as the natural) derived from the same letter "b" that gave us the flat symbol in music (♭).  These symbols developed because in early attempts to record music (around the 12th century or earlier), the note B was the first (and for a long time the only) note that seemed to require modification.  To distinguish between the different versions of B they would add a notation using "b rotundum" (the round b), "b quadratum" (square b) and "b cancellatum" (barred b).

I haven't given this a complete study, so I don't know exactly when and how these morphed into our modern flat, sharp, and natural symbols.  But around 450 years ago, notation began to use multi-lined staffs to write the notes, often five line staffs but sometimes more.  In 1575, Queen Elizabeth granted a printing monopoly to Thomas Tallis and William Byrd as exclusive printers of music.  Movable type was applied to the printing of music, and I believe this helped to standardize developing notations.  Their early published pieces included flats which are easily recognizable but the sharps looked more like a double X (and nothing at all like any form of "b").

From Cantiones Sacrae, 1575, Thomas Tallis and William Byrd (via hathitrust.org).

Some forms even looked a bit like a flower.

From A Compendium of Practical Music in Five Parts, 1667, Christopher Simpson (via googlebooks)

Soon the sharp began to look more familar.

Sample of sharps and flats used in text rather than music, from A Preliminary Discourse to a Scheme Demonstrating the Perfection and Harmony of Sounds, 1726, William Jackson (via googlebooks)

Of course in modern music, the sharp looks noticeably different from the number sign, and in our digital world they're two separate characters, which also differ in appearance.  Here they are in this font:

Number:        #

    Sharp:       ♯.

Proofing

There's one other very old form of # which could be even older than the sharp sign (at least in recognizable form).  In the printing process, after a page of text and figures has been "locked up" in a "form", a proof is printed from the form and checked for errors, after which the form can be corrected.  There's a standard set of notations for marking these errors for correction (because the corrector is usually not the same person as the compositor).  The # symbol is used in the margin to mark lines where a space is missing (and the spot on the line is marked with a caret or slash). This same notation is still in use today.  The oldest reference I know of on printing, Joseph Moxon's 1683 text, also describes this notation:

From an 1896 reprint of Moxon's Mechanick Exercises or the Doctrine of Handy-Works Applied to the Art of Printing, Vol. 2, 1693 (via hathitrust.org).

Of course, Moxon was reporting it, not inventing it, so the usage must be quite a bit older than 1683.

In addition, volume 1 of this reference includes a standard layout for the compositor's cases.  The # is used here to mark the sort that other sources say is for spaces or large spaces (bottom row).

From an 1896 reprint of Moxon's Mechanick Exercises or the Doctrine of Handy-Works Applied to the Art of Printing, Vol. 1, 1693 (via hathitrust.org).

You might think, as I first thought, that this sort was where the number signs were kept, but this isn't so—other sources clearly mark it for spaces.  This leads to a question though, where in the case was the number sign?  It simply didn't exist as a standard printable character.  Perhaps you noticed that in my 1726 image above, the sharps appear to be hand-drawn (or more likely hand-carved characters).  Sharps were standard for music printers, but other than that, nothing like a number sign existed in the standard fonts.  Of course, many fonts had "specials", and much later on it it became  more common for specials to include a number sign, although the exact details are difficult to track down.

Tic-Tac-Toe

Another very old usage for this symbol is as a Tic-Tac-Toe board.  In printed descriptions, this is the third oldest form (based on what I've found so far), with a clear description of the game from 1823 under the name "Kit-Cat-Cannio" (Suffolk Words and Phrases; although they do not reproduce the game board).   An 1852 reference shows a game board, as shown below.  For reasons that belong in another post, I tend to suspect the game as we know it (and more to the point of this article, the game board) developed during the 1800s or at most the late 1700s.

From The Book of Children's Games, Constance Wakeford Long, 1852 (via googlebooks).

Number

In 1853 I find this symbol described in a reference as an abbreviation for "number".  This is the earliest description of this usage I've found so far.  However three years earlier (1850) I've found the symbol used in account ledgers as a pound sign.  Which usage came first?  Safe bets at this point are that the printed description of number in 1853 trumps pound usage "in the wild" in 1850, because to be described the number usage had to be quite common.  And the earliest description of the pound usage I've found is thirty years later.  Still, I've barely scratched the surface in references so who knows what might turn up next?  At any rate, my assumption now is that usage as "number" is older than "pound".

From An Elementary Treatise on Book-keeping by Single and Double Entry,  1853 (via googlebooks).

Still, this usage remains quite perplexing.  In spite of the above description, I have so far not found any actual usage of it as such prior to the introduction of the typewriter.  Many of the sources that mention this usage do so in the context of business (or commerce or retail or something similar).  And yet I have still seen no sign of this symbol on old ledgers or inventories or anything of the sort.  I don't doubt that examples exist, I just haven't found them yet.

It's also a bit odd that there's no particularly compelling theories on how the number usage originated, even though we have tons of (bad) theories on the pound usage.  In print "number" is usually written out, but if it is abbreviated, it is either done as "No.", or as a single character that was apparently not uncommon to printers: №, as in "№ 2".  It's not clear if there's any relationship between the № and # characters, but there is a clear street use versus print dichotomy which I'll cover in more detail in the next section.

Pound

There's a number of theories out there on how this came to be used as a pound sign that all seem to center on confusion between the apparently American number sign and the British pounds sterling sign (£), relating to other technology like the telephone, the typewriter, the Baudot code (the first digital encoding scheme for the telegraph), or other early telegraph codes.  The Baudot code theory is by far the most common.

The telegraph system was invented in the late 1830s, more or less simultaneously in the United States by Samuel F. Morse and in England by Charles Wheatstone and William Cooke.  By the 1850s this "Victorian Internet" was changing the world.  And then in the 1870s, a Frenchman named Émile Baudot began tinkering with automatic decoding and printing of telegraph signals.  To do this, he invented a totally new code, a five digit binary code.  The claim is that American and British versions of this code used the number sign and pounds (sterling) sign in the same place.  There's a number of problems with this, a big one being that the Baudot code itself was almost never used in the United States.  Another big problem is that (despite an unsourced claim in Wikipedia) I can find no evidence that such a code collision ever occurred.  At least not exactly.  French and British codes overlapped the numero (№) and pound sterling (£) on the same code (shift-N).  However it isn't clear if # ever had dual meaning anywhere in Europe, or if it was an entirely American symbol.  Even if codes had overlapped, an obvious issue is that American usage of 12# (weight) and British usage of £12 (currency) are easily distinguished both based on order and context.

But of course the biggest problem is the timeline.  The # symbol already had dual meanings by 1853, and almost certainly much earlier.  This precludes any technology interference except possibly the original telegraph codes.  But again, I find no evidence of collisions (and in fact, no evidence that the number sign had any encoding at all) in any of the common telegraph codes of that era.

This all makes it seem more likely that if there was any confusion or overlap, it went in the opposite direction—documentation of a variety of different national code sets were confused by the pre-existing double meaning of #.  Or perhaps, if # was used or known in Europe, the double meaning even encouraged the use of the same code slot for these meanings.

The most popular theory and almost certainly the right one (in my opinion) is that the pounds meaning derived from the common usage of lb as an abbreviation for pounds, or more specifically for the latin "libra pondo".  This abbreviation of "lb" or "lbs" was common both then and now, but in addition to the abbreviation, it was also used as a symbol, by crossing a line through the letters like this: ℔.  (Some sources distinguish ℔ and lb. as pounds Troy and pounds avoirdupois respectively, however I haven't seen enough consistency across the long span of these usages to say that this is an accurate or useful distinction).  This notation goes back at least to Isaac Newton's time, as noted in online sources.  Here's an enlarged version of one of his ℔ symbols, together with a sample showing his use in context.

Isaac Newton's pound symbol, 1692 (via chemheritage.org).

As you can see, in its usual cursive form, it already looks a bit like a pound sign.  Note how he has used ℔ as a superscript.  I've found this it be a highly consistent usage in handwriting from his time through the 19th century, and one that helps convince me of the # usage when it turns up.  It's quite easy to find ℔ in old handwritten receipts and ledgers, as well as "lbs."  However use of an actual # is not that common.  I first found an 1887 receipt that includes 302 pounds of cheese (shown as 312-10=302) sold at 12 cents per pound for $36.24:

Unmistakable pound sign, 1887 receipt (via 19th Century Wellington blog).

Later I found this example from 1850.  It includes two pound signs, although the second one is smudged.  It's from a ledger in Hustonville Kentucky from 1850 and includes a line with 7-1/4 pounds of nails, then later 6 pounds of nails.

Two pound signs (one clear, one smudged), 1850 (via Kentucky Digital Library).

Early on it's even harder to find it described in a text than it is to see it in use.  The first mention in print I have found so far is this 1880 book, where its dual usage as both number and pound is mentioned:

From Book-Keeping by Single and Double Entry, 1880 (via archive.org).

This mention comes thirty years after I see it "in the wild".  Of course it has to be fairly common to be mentioned in a book at all.  My assumption is that there was common usage among the people, in markets and in handwriting, where the symbol was long used to mean both number and pound.  And then there was the printing business, dominated primarily by academic concerns, and where these notations would be written out fully, or at least abbreviated in the more traditional printers' way as ℔ and №.  These two worlds rarely collided which is why it was so long before this usage was acknowledged.  This is supported by the fact that the character used in the above sample seems to be a sharp symbol, not a pound or number sign—they couldn't actually print the literal character in common usage on the streets, because even by 1880 it was still very unusual in typography.

Two technologies seem to confirm this notion: the Linotype, and the typewriter.  The Linotype was an extension of printing technologies.  The typewriter on the other hand was a replacement for people's handwriting.  The first typewriter in 1873 had no number sign (and no lower-case letters for that matter), but by 1886 at the latest, there it was, above the three, right where it is today.  Contrast this with the first Linotype that came out in 1886.  It had a rack of 72 matrices that could be used to mold characters.  None of them was a number sign.  But then, by 1906, Linotype had expanded to a 90-character rack of matrices.  But still no number sign.  It did however have the ℔ symbol.  Even by World War II, there was no standard number sign included in most Linotype fonts.  (And for the record, they existed, but were extras that had to be added in by hand, rather than from the Linotype keyboard.)

Diagram of Remington typewriter keys, from catalog ca. 1887 (via Harvard Library).

There's another clue hidden here that's related to the notion of printing versus handwriting.  If you go back and look at the full manuscript I linked to for that Isaac Newton reference, he seems to use a form of the ampersand that many still use today—a sort of a cursive plus sign.  It's a perfect example of common usage that we can all recognize, and yet it is very rarely mentioned in most printed documents.  This is possibly for the simple reason that its representation in typography is very rare.  In fact, I'm not even sure that version of the ampersand exists in Unicode.  If that form of ampersand can exist for so long without significant discussion, it gives me hope that there are some very old number signs and pound signs out there somewhere, represented as #.

Official name?

So you may have noticed that I have called this symbol a number sign a few times in this post as a more generic name.  Today, it's the most common usage (outside of social media of course).  It's seldom used to mean pounds anymore.  In my opinion, because of the widespread use of the symbol in this context, together with a long history as the same, "number sign" is our best bet as a name for this symbol.

But you may be wondering about a couple of other common names.  One of them, the octothorpe, has at least two origin stories, both linked to different sets of employees at Bell Labs around 1963.  One of them is almost certainly close to the truth.  In 2014, one of the claimants wrote a pretty detailed piece on the history.  But even the authors didn't seem to want it to catch on, and for the most part it hasn't.  Despite a few sources that call it the "official" name, this seems to have been little more than a joke.

Which brings me to the other common name, the "hash", or "hash mark" or "hash sign".  I think that one deserves a posting all its own, so you'll have to wait to see how I demonstrate that the British are ruining the English language in part two.