Hello, Another great video, Professor Herning! Your less than enthusiastic endorsement of Picketts (and also Gary's comment here as well) prompts me to mention that of the dozen slide rules in my collection, the Picketts are the smoothest performing: the action is silky, but the slide holds its place quite nicely. (Of course, I gave them a Teflon dry lube treatment). Anyway, over the past year, they've become my favorite rules to use. But I still loathe the yellow color! (I've, finally, got a white Pickett coming in the mail this week.) But I'm also well aware that we all have our own personal slide rule esthetics! Anyway, your videos have inspired me to (as a relative newcomer) to collect a variety of techniques in one place. If you don't mind, I'd like to write up your tens-complement idea for dealing with logs of arguments between 0 and 1, on my blog, properly footnoted of course! You'll note that I've already plugged your videos there as the best resource ever. Of course, this is a non-commercial venture from a lover of slide rules: slide-rule-mania.blogspot.com/ Best wishes, Donatien
Thanks for another great one. I'm fond of the Reitz rules as well. I find Picketts hard to use. They usually aren't smooth sliders like the wood ones, especially Hemmi/Post bamboo rules. Also, while I know the yellow color is supposed to reduce eye strain (hence the -ES designation) I find them harder to read. That said, they are the only ones with a Ln scale, and one of the few with a LL4 scale, if you need either of those. Also, Buzz Aldrin took a Pickett 600-ES with him to the moon, so they have that going for the, which is nice.
A very uncommon non-duplex layout was the Yokota slide rule. Available from John Davis & Son in the UK from 1907 to 1938, it did the Darmstadt one better by having a set of three log-log scales and three inverse log-log scales, something that normally is only found on a duplex. Given Keuffel & Esser's jealous guarding of their monopoly on the duplex slide rule, why wasn't this type of slide rule more common?
As an aside, I thoguht I would point out that the so-called "Soho" slide rule of Boulton and Watt went for an A[B B]D arrangement. It seems to be the first time the advantages of the slide rule design concept and a non-trivial application where put together. NB: There is no cursor hence the double B. The Mannheim version upgrades this by including a cursor. cf. Farey’s treatise on the steam engine (1827). Just like Watt’s Soho steam engines, Watt’s Soho slide rules can be treated as a symbol of the break between merchant and industrial capitalism.
On the Post 1447 they key S to A and use the extra doubling of the A range to give angles from about 1 deg to 90. It seems this is a bad design as for small angles, sin x = x (rad), which can be computed easily on the C & D scales. This takes up about half of the physical scale and leaves only a small space for those from say 6 to 90 deg, i.e. those angles you really need the rule to compute. On the Rietz arrangement they, of course, correct this with the S and ST arrangement. What I don't quite get is why there is a preference for the Mannheim arragnement of A[B C]D over the folded arrangment as this squaring between the upper and lower robs one order of accuracing (i.e. you lose out on the 3rd significant figure)? The folded CF|DF seems to correct for this problem by keeping the graduation the same between the upper and lower scale sets. Is it simply an historical preferece? Or a preference for squaring calcuations? I like the Post 1445 folded arrangment as it corrects the above issues in a clean simply way (and I find the SI and TI more natural to use than just the S and T version). The only downside in the 1445 design comprimise is the graduations are not quite as good as that of a 10'' (particularly on the back). I'm guessing this is a marketing comprimise for a small 8'' rule. Taking the 1445 one step further, the front side of the Post 1450 arrangement of K, DF[CF, CIF, CI, C]D R1, R2 seems to give the best simple basic arrangment with good accuracy for general purpose computations.
Arrangements with folded scales were an alternative to the Mannheim layout even in its early days. I do like the ability to multiply or divide by a square root, easily chaining that with other calculations using the B scale. I was just having a similar discussion over on my new video on the 1462H. Let's say you design a simple slide rule with C, D, and A for the basics. Next, you'd like to add the ability to solve proportions without going off-scale (my example was converting a batch of grades out of 35 points to percents). The solution that uses the least scales is to just add B. You could also add CF/DF like on the 1445 and get greater precision but at the cost of one extra scale. This is the lens through which I see the Rietz and Mannheim layouts making a lot of sense. Especially the Rietz -- I think moving L to the front and A near K are good usability improvements. Solely having trig on the back is at least consistent. On the Rietz, though, there is no room for even one more scale on most frames (unlike Mannheim designs which often waste a little space with a brand name or model name). So, looking at the logic of the 1445: start with a Mannheim frame with room for one more scale on the front, then remove B and replace with CF/DF. You've used up the extra space with the folded scales instead of the ST scale essentially. I guess then, the Rietz solves the S scale resolution problem while the 1445 solves the proportion resolution problem.
These issues seem to lead directly to the various duplex solutions to the above compromises. The benefit of a double length A scale is that it is uses one scale and gives a good quick n easy way of doing squaring. Putting this with the general design principle that you want as many of the scales as possible on the slide (to doing multiple operations) leads to the idea of an A/B arrangement making good sense (at the lost of some resolution). On the other hand the folded scales have advantages, hence what you'd like is both CF/DF and A/B on the slide. The duplex design allow you to achieve this in a nice way. As was pointed out earlier, the K&E 4081 offers what seems to be the most compact and symmetrical arrangement. They go for A/B on the back (with advantages of trig on the slide) so giving the Mannheim arrangement by flipping. The Post 1460 offers a rival solution by initially doing away with the A/B (due to the poor resolution) and goes for an R1 R2 arrangement (at the expense of fiddling with two scales that are fixed to the base, i.e. no chaining possible) with a C/D on the back instead. The Post 1460 v2 puts an A scale back (so confirming its advantages). The squaring issue seems to be the main distinction between the duplex solutions (as resolving it leads to some compromise and affects the layout). e.g the K&E Deci-Lon solution seems to be a "have your cake and eat it" solution whereby the simplicty of the original slide rule design starts to wane. It would be interesting to compare the speed, accuracy and ease between the different squaring solutions.
Thank you for showing the different scale sets! Most of my slide rules are quite clear in that respect, but I couldn't categorize my Relay R-816 until now. It uses what you called the "folded scales set" with K DF [CF CI C] D A and trig on the back. From its appearance it's nearly the same as the Post 1445 you show. But unlike the Post 1445 the folded scales on the Relay are labelled with sqrt(10) instead of pi. Do you know what the reason might be?
You're welcome! It sounds like your rule might be very close to the Hemmi 45k which is the Japanese-market version of the 1445. From the standpoint of keeping things on-scale, sqrt(10) is the best place to fold the scales. It's exactly in the middle of C or D, so you theoretically always have a way to set up a proportion so that everything is on-scale either on the normal C/D or on CF/DF. The downside is that you lose the ability two quickly multiply or divide by pi by switching between normal and folded scales.
its interesting you mention the picket 120 i have one coming in the mail . also a picket 121. i also have a book on trig and the slide rule coming . i suppose id better learn how to use them now lol i have a friend that is a physics teacher and he likes to challenge his students this may be a fun test of skills for them. for myself im a samiture machinest working with turn of the century machinery and if herd calculating rpm changes with pulleys is easily done with a slide rule so i thought it might be fun for my viewers . i suppose this is a proportion problem.
If you are in the US, maybe look for a Post 1447 or Pickett 902 in good condition. Almost any general slide rule had the basic scales though, so you may just want to look for something in good condition with K/A/B/C/CI/D maybe L. No B can be okay. I would try not to spend much over $20. Watch eBay for a few days and something will come up.
Thanks for the effort! Am havng aristo reitz 89 slide rule. I want know to learn the scales and all it's uses . kindly make a video on it. it Will very helpful for us in India. Thank you
Hey Sadeesh, I don't have an Aristo 89, but I believe it's similar to the Rietz Rule I show here that I use in a lot of videos. Try starting with my "Basic Slide Rule" or "Learn the Slide Rule" playlists. Leave a comment if you're having trouble applying it to the Aristo 89, and I'll try to help. The main difference with the Aristo 89 will be that the trigonometric scale (S, ST, and T) are marked in Degrees and Minutes instead of decimal degrees like in most of my trigonometry videos.
Hello,
Another great video, Professor Herning! Your less than enthusiastic endorsement of Picketts (and also Gary's comment here as well) prompts me to mention that of the dozen slide rules in my collection, the Picketts are the smoothest performing: the action is silky, but the slide holds its place quite nicely. (Of course, I gave them a Teflon dry lube treatment). Anyway, over the past year, they've become my favorite rules to use. But I still loathe the yellow color! (I've, finally, got a white Pickett coming in the mail this week.) But I'm also well aware that we all have our own personal slide rule esthetics!
Anyway, your videos have inspired me to (as a relative newcomer) to collect a variety of techniques in one place. If you don't mind, I'd like to write up your tens-complement idea for dealing with logs of arguments between 0 and 1, on my blog, properly footnoted of course! You'll note that I've already plugged your videos there as the best resource ever. Of course, this is a non-commercial venture from a lover of slide rules: slide-rule-mania.blogspot.com/
Best wishes,
Donatien
Sorry for not seeing this comment sooner! Go ahead and write up any technique you like.
Just checked out your website. Looks great!
Thanks for another great one. I'm fond of the Reitz rules as well. I find Picketts hard to use. They usually aren't smooth sliders like the wood ones, especially Hemmi/Post bamboo rules. Also, while I know the yellow color is supposed to reduce eye strain (hence the -ES designation) I find them harder to read. That said, they are the only ones with a Ln scale, and one of the few with a LL4 scale, if you need either of those. Also, Buzz Aldrin took a Pickett 600-ES with him to the moon, so they have that going for the, which is nice.
A very uncommon non-duplex layout was the Yokota slide rule. Available from John Davis & Son in the UK from 1907 to 1938, it did the Darmstadt one better by having a set of three log-log scales and three inverse log-log scales, something that normally is only found on a duplex. Given Keuffel & Esser's jealous guarding of their monopoly on the duplex slide rule, why wasn't this type of slide rule more common?
As an aside, I thoguht I would point out that the so-called "Soho" slide rule of Boulton and Watt went for an A[B B]D arrangement. It seems to be the first time the advantages of the slide rule design concept and a non-trivial application where put together. NB: There is no cursor hence the double B. The Mannheim version upgrades this by including a cursor. cf. Farey’s treatise on the steam engine (1827). Just like Watt’s Soho steam engines, Watt’s Soho slide rules can be treated as a symbol of the break between merchant and industrial capitalism.
On the Post 1447 they key S to A and use the extra doubling of the A range to give angles from about 1 deg to 90. It seems this is a bad design as for small angles, sin x = x (rad), which can be computed easily on the C & D scales. This takes up about half of the physical scale and leaves only a small space for those from say 6 to 90 deg, i.e. those angles you really need the rule to compute. On the Rietz arrangement they, of course, correct this with the S and ST arrangement. What I don't quite get is why there is a preference for the Mannheim arragnement of A[B C]D over the folded arrangment as this squaring between the upper and lower robs one order of accuracing (i.e. you lose out on the 3rd significant figure)? The folded CF|DF seems to correct for this problem by keeping the graduation the same between the upper and lower scale sets. Is it simply an historical preferece? Or a preference for squaring calcuations? I like the Post 1445 folded arrangment as it corrects the above issues in a clean simply way (and I find the SI and TI more natural to use than just the S and T version). The only downside in the 1445 design comprimise is the graduations are not quite as good as that of a 10'' (particularly on the back). I'm guessing this is a marketing comprimise for a small 8'' rule. Taking the 1445 one step further, the front side of the Post 1450 arrangement of K, DF[CF, CIF, CI, C]D R1, R2 seems to give the best simple basic arrangment with good accuracy for general purpose computations.
Arrangements with folded scales were an alternative to the Mannheim layout even in its early days. I do like the ability to multiply or divide by a square root, easily chaining that with other calculations using the B scale. I was just having a similar discussion over on my new video on the 1462H. Let's say you design a simple slide rule with C, D, and A for the basics. Next, you'd like to add the ability to solve proportions without going off-scale (my example was converting a batch of grades out of 35 points to percents). The solution that uses the least scales is to just add B. You could also add CF/DF like on the 1445 and get greater precision but at the cost of one extra scale. This is the lens through which I see the Rietz and Mannheim layouts making a lot of sense. Especially the Rietz -- I think moving L to the front and A near K are good usability improvements. Solely having trig on the back is at least consistent. On the Rietz, though, there is no room for even one more scale on most frames (unlike Mannheim designs which often waste a little space with a brand name or model name). So, looking at the logic of the 1445: start with a Mannheim frame with room for one more scale on the front, then remove B and replace with CF/DF. You've used up the extra space with the folded scales instead of the ST scale essentially. I guess then, the Rietz solves the S scale resolution problem while the 1445 solves the proportion resolution problem.
These issues seem to lead directly to the various duplex solutions to the above compromises. The benefit of a double length A scale is that it is uses one scale and gives a good quick n easy way of doing squaring. Putting this with the general design principle that you want as many of the scales as possible on the slide (to doing multiple operations) leads to the idea of an A/B arrangement making good sense (at the lost of some resolution). On the other hand the folded scales have advantages, hence what you'd like is both CF/DF and A/B on the slide. The duplex design allow you to achieve this in a nice way. As was pointed out earlier, the K&E 4081 offers what seems to be the most compact and symmetrical arrangement. They go for A/B on the back (with advantages of trig on the slide) so giving the Mannheim arrangement by flipping. The Post 1460 offers a rival solution by initially doing away with the A/B (due to the poor resolution) and goes for an R1 R2 arrangement (at the expense of fiddling with two scales that are fixed to the base, i.e. no chaining possible) with a C/D on the back instead. The Post 1460 v2 puts an A scale back (so confirming its advantages). The squaring issue seems to be the main distinction between the duplex solutions (as resolving it leads to some compromise and affects the layout). e.g the K&E Deci-Lon solution seems to be a "have your cake and eat it" solution whereby the simplicty of the original slide rule design starts to wane. It would be interesting to compare the speed, accuracy and ease between the different squaring solutions.
Thank you for showing the different scale sets!
Most of my slide rules are quite clear in that respect, but I couldn't categorize my Relay R-816 until now. It uses what you called the "folded scales set" with K DF [CF CI C] D A and trig on the back. From its appearance it's nearly the same as the Post 1445 you show.
But unlike the Post 1445 the folded scales on the Relay are labelled with sqrt(10) instead of pi. Do you know what the reason might be?
You're welcome! It sounds like your rule might be very close to the Hemmi 45k which is the Japanese-market version of the 1445. From the standpoint of keeping things on-scale, sqrt(10) is the best place to fold the scales. It's exactly in the middle of C or D, so you theoretically always have a way to set up a proportion so that everything is on-scale either on the normal C/D or on CF/DF. The downside is that you lose the ability two quickly multiply or divide by pi by switching between normal and folded scales.
its interesting you mention the picket 120 i have one coming in the mail . also a picket 121. i also have a book on trig and the slide rule coming . i suppose id better learn how to use them now lol i have a friend that is a physics teacher and he likes to challenge his students this may be a fun test of skills for them. for myself im a samiture machinest working with turn of the century machinery and if herd calculating rpm changes with pulleys is easily done with a slide rule so i thought it might be fun for my viewers . i suppose this is a proportion problem.
I really want a slide rule - what would you recommend as the best starter slide rule for basic math?
If you are in the US, maybe look for a Post 1447 or Pickett 902 in good condition. Almost any general slide rule had the basic scales though, so you may just want to look for something in good condition with K/A/B/C/CI/D maybe L. No B can be okay. I would try not to spend much over $20. Watch eBay for a few days and something will come up.
@@ProfessorHerning Thank you!
Thanks for the effort! Am havng aristo reitz 89 slide rule. I want know to learn the scales and all it's uses . kindly make a video on it. it Will very helpful for us in India. Thank you
Please make a video explaining the uses of aristo reitz 89 k to L scales with S & T scales. It will be very helpful for us. Thank you sir
Hey Sadeesh, I don't have an Aristo 89, but I believe it's similar to the Rietz Rule I show here that I use in a lot of videos. Try starting with my "Basic Slide Rule" or "Learn the Slide Rule" playlists. Leave a comment if you're having trouble applying it to the Aristo 89, and I'll try to help. The main difference with the Aristo 89 will be that the trigonometric scale (S, ST, and T) are marked in Degrees and Minutes instead of decimal degrees like in most of my trigonometry videos.
Professor Herning sure sir.. I will start with those videos. and thank you for the reply
J'ai 140 regles a calcul faber castell tout neuf made in allemagne en 1965.N°57/88 N°57/89 Avendre