
This is the ruler that started it all for me, a Stanley #61 boxwood two-foot, four-fold, square-joint ruler with middle plates, manufactured between 1855 and 1957. This particular one could be pre-1949.
Even a quick glance through Alvin Sellen’s book encyclopedic book Stanley Folding Rules will give you a sense of the vast variety of these that were manufactured from the mid 19th to late 20th century by Stanley, Lufkin, Rabone and other tool companies. Carpenters, shipwrights, surveyors, blacksmiths, patternmakers and a host of other trades all had their own rulers with features suited to their particular work. In case you don’t already waste enough time on line, take a moment to hop on eBay and search for “folding rulers” to see how many of these are still around and just waiting for you to buy them. The wooden ones are nice, but in the mid 19th century they were also made from ivory and oxbone with German silver mounts, and those are really lovely (with a price to match).
No question, then, that they make great collectibles, but are they really useful in the shop? For me, at least, the answer would be an enthusiastic “yes.” One of the things we’re blessed with in the 21st century is choice–just think of how many things there are to eat for breakfast in the average grocery store, for instance. It’s no different in the workshop. Need to cut something? If you have any kind of workshop at all, I bet there’s at least 6 different ways to accomplish the same purpose ready to hand (I took a moment to count my own stuff: compound mitre saw; tablesaw; bandsaw; 2 different sizes of Skilsaw; several japanese saws; several western hand saws). Obviously if I have to measure off a 6′ piece of stock I’m not going to use my four-fold, two-foot folding ruler three times in a row. But for smaller measurements around a traditional boatbuilding project, these folding rulers work very well. As an added benefit, and here’s where the choice comes in, I find them just plain enjoyable to use (which I suppose is the same thing that someone else might say about their LED-equipped digital laser tape measure), and so use them I do. It’s a pleasure to have something in your hand that offers a connection to people who used to do what you’re doing now. Folding rulers also look very official sticking out of your back pocket or apron, and if you’re working in public, they’re great conversation starters.
Did I mention that these kinds of rulers are available on eBay? and from antique tool websites, antique tool shows, flea markets and garage sales? I still have and use the Stanley #61 that Peter gave me more than 15 years ago, but that hasn’t stopped me picking up a few more over the years. Here’s some favourites from the “measuring” drawer of my tool chest. These are all tools that I’ve collected to actually use, so I tend not to go for the pristine examples, or pay extra for an original box, but concentrate instead on pieces that are straight, solid and ready to work.

Here's a sentimental favourite. It's a four-fold, arch-joint caliper ruler with no visible maker's mark. The outside is very worn from years of travelling in someone's pocket, but the inside markings are still clear and usable. Two higher-end features are the arch-shaped joints at the hinge and the brass binding on the edges. I carry this in my pocket nearly every day just for the pleasure of having it around.

Here's one I couldn't resist. It's a tiny Stanley 65 1/2, one-foot four-fold, brass bound with a square joint. This type was manufactured from 1855 to 1934, and this particular one dates from some time after 1867.

A Lufkin #42 boxwood Shipwright's Bevel. Competition was fierce in the ruler business, and Stanley offered an identical piece, also a #42, albeit with square ends on the brass bevel arms.

Here's a kind of Swiss Army Knife folding ruler. This big, chuncky four-fold two-foot Rabone # 1190, possibly from the 1930s, has an arch-joint and engraved hinge marked with degrees for use as a bevel gauge, as well as a brass level.

A Stanley #136, manufactured between 1932 and 1983, incorporating an inside/outside caliper as well as a ruler on the other side.

A Lufkin #41 3-fold, one-foot steel ruler with case. The leatherette case for this model was often embossed with a company's name so it could be used as a promotional item.
Some great sources for rulers like this include eBay; Jim Bode Antique Tools; Vintage Tools and Bob Kaune Antique & Used Tools.
Until next time. . .