Antique Ivory Ruler - How the Hell does this thing work!?

Honestly, I've given up on this thing! I turn to you folks for assistance!

I bought this last week at the local flea-market, as an accessory for one of my writing slopes (some folks here might remember that I collect them). Anyway, I'm trying to understand what the heck this thing is, and exactly how it works and why it's set out the way that it is! Nobody I asked could give me an answer. I've never seen anything like it, and I have seen a LOT of antique ivory rulers!



It is 12 inches long.



It was sold by F. Robson & Co., 46, Dean Street, Newcastle-on-Tyne, in England.

I have researched F. Robson & Co. It's still around...and it's still in N-o-T. Its field of business is optical equipment. It was established back in 1867, and once made all kinds of measuring devices - rulers, slide-rules, barographs, folding rulers, etc, etc.

This is the company's current website:

http://www.robsonopticians.co.uk/

That is as much as I've found out. Now, here's the puzzling bit.

This ruler measures INCHES. But the markings on the ruler are NOT IN INCHES.

They are markings for...:

3/8th inches.
1/2 inches.
1/4 inches.
1/8th inches.
3/4 inches.

And there's more measuring markings, which I can't read. There's four on each side of the ruler, two at each end, and two lines of measurement on each edge of the ruler, on both sides. I would photograph them, but they're almost impossible to read.

What I want to know is - WHY? Why is it set out like this? What's the purpose? I've never seen anything like this!

I have emailed the company and await a reply. See if they can dig up a reason or any information...

 

I can't see it clearly enough, but from your description it sounds like a draftsman's scale, used to make scale drawings such as floor plans, etc. For example, 1/4 scale would mean that each 1/4" of of the drawing would represent 1 foot, etc.

 

Yes, I can't see it but it does sound like a scale ruler.

 

This thread reminds me of a Victorian Silver filigree tape measure I bought a while ago, The silk tape inside is in lovely condition but what makes it interesting is the measurements are in Nails, A Nail is an old measure and is the equivalent 2¼ inches.

 

Used for cloth, wasn't it?

 

http://www.traditionaloven.com/tuto...g-unit-to-nail-cloth-length-unit-measure.html

When I was at primary school they taught us this stuff along with rods, poles or perches. Metrication came far too late.

 

Can you still draw a straight line with it?

 

Yes, The nail was named after the method of hammering nails into the counter where cloth was sold.

 

Its amazing, the things I DO remember...................and just about getting dangerous with the things I DON"T

 

I know what you mean, I can remember things from years ago but can forget something from a few days ago......Scary

 

I can remember my friend's dog's name from circa 1975, but not the name of the person singing harmonies in church yesterday.(sigh) Scale rulers are pretty cool, but they're out of use these days. Computers took over most of the hand-drafting back in the 80s.

 

That's why I have an even dozen scales and 3 t-squares, 2 drawing boards, 2 electric erasers, a gazillion pens, 3 pencil pointers, and about 4 dozen templates, specialized and standard.....

 

I don't have that many, but do have a t-square floating around, as well as a wooden triangle, and three drafting kits. I inherited two of those but bought the third in a thrift. Since I draw for fun, it does get used.

 

Even my "fantasy" residential design these days is done on the PC. Haven't done any serious work in about 40 years. Last project was a house on stilts in the Everglades - built around an open air "shower" courtyard.

 

I just hope the owner never finds him/herself up to the proverbial in alligators. Not that clothing would provide any protection but showering outdoors leaves all sorts of dangly bits exposed.

 

Oh, yeah!!! Don't ask why I am certain about that! But this place is 6" above the water with the house built around a court yard that is the shower. Screened across the top. Very "cool" place in a very hot place..............