Kyle Rankin @kyle@librem.one

To add, insert a stylus in the number for the appropriate column *below* the totals, and slide downward. If the addition (I added 5) overflows, the corresponding column in the total turns red, alerting you that you need to go up and around the "shepherd's hook" to carry the one.

This is a Produx pocket calculator. It was designed by Otto Neuter and produced in Germany starting in the 1930s. I suspect this particular one was from the 1950s or maybe `60s, due to the coloring and the reference to West Germany on the back.

@ajmartinez Congratulations!

@Konqi That is a very similar model as mine, but with a few more rows of digits. Beautiful machines.

For adding machines of that era the Comptometer is faster for pure number crunching, but then with the Comptometer you couldn't print out your calculations on paper tape or a ledger like the Burroughs.

@edsu Straight razor has similar techniques to safety razors but you alternate between left and right hands, and the only thing guiding you to the right cutting angle is you, no bar or guide.

When I grew a beard last year I used a straight razor to clean up my neck/face. My best shaves are from a straight razor, but I use a safety razor normally, because of a few mishaps w/ a straight razor where I missed the angle on my chin and dug in :). I decided to stop before I got a scar.

@edsu Difficulty has a lot to do w/ different margin for error. Modern disposable razors flex and are more forgiving. Safety less so, straight razors leave little room for mistakes. Bad angle/technique and you cut yourself.

Classic mustache/beard patterns coincidentally grow hair in the places hardest to shave w/ a straight razor.

I recommend learning safety razor shaving first to learn angles and technique, then move on a straight razor. Get a Dovo Shavette that uses DE blades and GO SLOW :)

@owingst Yeah realistically I only change blades every two weeks or so myself, and that's with Extras. I hear Premiums hold their edge even longer so I really do think I'm set until the 2030s.

@mc@mastodon.sdf.org I don't know, I just discovered these existed yesterday. I had been happy enough with my Derby Extras (and felt they were sharp enough for me) that I hadn't really ventured out into fancier (and more expensive) blades like Feathers, although I know there are plenty of people who swear by them.

I shave w/ Derby Extra blades, $10 for 100, but was shopping for something new. Discovered Derby Premium for a similar price, but a 2-pack (200 blades!) was on sale for $14. At 1/week this is a 4-year supply. At my rate I won't need blades again until my son is in college.

@Konqi The Burroughs Class 1 wins for overall aesthetics with the beveled glass sides and it is the one I'd put on most prominent display inside a home.

@Konqi Of the pocket calculators it would have to be the Addiator Duplex, which I will feature in a few weeks.

Between the desktop ones I own that's a tough call! I haven't featured all of them yet but probably would choose either the Comptometer or the Monroe LN-160x if I had to pick one to use for real work. The former for addition and multiplication, the latter if I also needed to do a lot of subtraction and division.

To zero things out, you pull on a lever at the top. Basic tallying, like scrabble scores, can be done pretty quickly on one of these after some practice. You can also do multiplication via repeated addition and left shifts like with other adding machines.

To subtract, you slide a panel from the bottom upwards, which aligns new numbers with the holes. Now you slide up instead of down, unless you need to carry a one, in which case you slide down around the hook. I'm not a fan of this part of the design--it is pretty cumbersome.

As you slide rows down you notice some numbers in a row are colored red. That signals that when you add those numbers, instead of sliding down, you slide up and around the "shepherd's hook" to carry the one. Here I added 5.

This is a Tasco Pocket Arithometer. It was probably made in the 1940s but is based off of older Arithometer designs. It is sized to fit easily into a shirt or coat pocket. To add numbers you place a stylus in the appropriate row and drag down, which adds to the existing total.

@mc@mastodon.sdf.org You should check out local thrift or antique stores. Often you can find nice vintage razors for $10-15 that just need some cleaning. I have a knock-off of a Merkur Futur adjustable but I find I prefer my vintage razors.

@lwriemen Many 3D printers themselves use 3D-printed gears, so they at least can hold up to those stresses. In this case the teeth are small enough they might not hold up so well to constant stress against metal gears.

@mc@mastodon.sdf.org Yes, I rotate through my razor collection and shave with just about all of them. I just shaved with this red tip this evening as I had never shaved with one before. I already have a slim in my rotation so I know how it shaves.

Today's other antique find is this pair of mechanical pocket calculators. Both came with their original case but sadly neither had their stylus.

Each pocket calculator in my collection has a slightly different way of performing arithmetic, probably due to patents.

Today's antique finds: a Gillette red tip and a Slim adjustable. The red tip came with a wooden case which I don't think is original--my understanding is these originally came in a plastic case.