The case for this model is the standard form-fitting black cardboard with leather closing flaps bolted on. I've also included a scan of the first page of a tattered set of instruction sheets for this model rule. Frankly, I must say that I prefer the quality of the older leather cases! Ah well, that's progress for you. in the US and the Hughes Owens Co. Please check out the remaining rules on this page for a detailed comparison. This Beginners rule is just that. I know it wasn't long before the Geotec brand name and logo replaced the Hughes Owens labels on the actual rules. Their high quality leather cases are also among the best, and were frequently imitated. Dating k&e slide rules. Also included in its own scan up above is the warranty/care and maintenance insert that was sold with high-end HO rules. In fact, this rule has one the whitest patinas I've seen on a rule of this age. I haven't bothered scanning in the edge or inside views, as they are identical to the later one above. Also, note the internal scale behind the slider on the third scan. I've a fondness for rules used in Canada, though, hence my preference for Hughes Owens models. Still a very solid and professional looking slide rule. I would love to have seen what else they might have come up with! The smallest functional slide rule I've ever seen! This diminutive pocket model sports a built-in domed magnifying cursor and a beautifully worn Post leather case. Aside from the illustration of the rule and the French HO warranty card inside, there is no mention of Hughes Owens anywhere in this manual! It even goes so far as to refer to the rule as a "Hemmi No. Imprinted in gold lettering on the flap is the Hughes Owens name and model number, along with the words "HEMMI'S SLIDE RULE" on the brass button. The most obvious change is the relieved mahogany wood exposed on the edge pieces of the rule, along with the model and patent information. The main differences are the reduced number of scales on this rule, with their simpler monotone appearance and less intuitive layout as you might expected from an older rule. The first difference you'll notice is that all of the rule's descriptive product information and bona fides on listed the edge instead of the face, as was standard on earlier model rules. Later versions come in the standard Hemmi two-tone blue/white plastic cases with the Geotec logo. Unfortunately, the cursor is missing, which would have helped pin the date down a little.
Slide Rule Dating - K&E Catalogs Main Page. Faber abandoned it by WWI, as apparently it was considered too difficult for most people to use. The table of contents on the back differs from later models, and includes such interesting measures as the "Ultimate Strength" of various woods and metals in pounds per square inch. A most unusual find, and clearly my oldest Hughes Owens rule to date. A very popular and sought after rule, I managed to snag this one in the original box with hard cover manual shown above. Unfortunately they didn't survive intact, but their final assets were eventually acquired by the reproduction paper and film company Azon, which also bought out what was left of the Frederick Post and Hughes Owens companies. Dating k&e slide rules. The case has also been subsequently imprinted with the former owner's name, Clarke & Stuart Co., Ltd., of Vancouver B.C. The rule has an excellent feel, and is made of celluloid covering a mahogany wood core. In fact, the "S" in the title refers to the label on the case, and presumably reflects the "stitched" all-leather case design. This rule predates Post involvement with Hemmi, and thus there is no Post equivalent that I'm aware of.
Slide Rule Dates and Time-Lines. The manual is in excellent condition, with the pages still very white. Inside the manual, the diagram of the rule features the Hughes-Owens name on the stator and the Geotec logo on the slider, despite the presence of the HO logo on this particular rule. The cursor is the later model metal-framed glass, which I believe came into play sometime shortly before the second world war. The case is also made of the older all-leather style, with the hinge pieces sewn on instead of bolted. These rules could well be considered the standard bearer of slide rules! For a comparison, you might want to check out my Dietzgen page for some competing similar models of the same time period. The second letter corresponds to the month, with A for January, B for February, etc. it's interesting to see how quickly it started to change. It's such a great rule, I would have though K&E would have made more of them. The set is complete with Hemmi's two-toned plastic case, manual and original cardboard box. Relationship of pressure and volume. A nice early production model of this rule. Seems like a good idea, rather than marking up the leather. That would certainly fit in this rule's serial number and design features.
Sun Hemmi Slide Rules - Eric's Slide Rule Site. Dating this particular specimen is especially difficult, as this model is only listed in the three earliest Hughes Owens catalogs, and doesn't exactly match any of the illustrations. check it out for a comparison. The back of the rule has the standard conversion factors. I just can't say enough nice things about this design. Made apparently of light-weight pressed wood, this model has a simple white-painted face with printed monotone scales, very reminiscent of the inexpensive Lawrence Engineering rules. Virtually identical in construction to the Versalogs, although this one has a simpler black leather case which seems inferior compared to the richly coloured Versalog case shown above. This particular rule also features the high-end K&E all-leather orange coloured case with chamois-like interior. Overall, still a nice mahogany/celluloid rule, sharing the same fundamental design as later rules. In this case, very similar to the model presented above, but with a few slight changes. Made of celluloid on mahogany, they feature an excellent and extensive scale arrangement. but still a minor quibble for such a well-designed rule. I've seen various types of paperboard/vinyl sleeves to protect the rule, and a decent enough model is shown in the high resolution scans. Please note that some of the estimated dates have undergone recent revision, thanks to Clark McCoy's excellent reference set of various K&E catalogs. One little oddity about this particular rule: when I received it, I noticed that one of the pieces of cursor glass was actually a prosthetic replacement! Shown in its own scan, it appears to be a piece of Plexiglass crudely cut to fit the cursor frame. Incredibly lightweight, but infinitely nicer than any of the all-plastic pocket rule I've seen. basic, functional, with no pretension to being anything more. Hemmi also made a number of plastic rules, which were generally of very high quality and compared well to other manufacturers. most of the time the exposed surfaces have aged to a creamy yellow colour. This student model rule features celluloid laminate over bamboo, and all the exposed bamboo on the back gives it a lovely look and feel. Naturally, it is also lacking the relieved wood edges, which didn't come along until a bit later. Interestingly, Hemmi still exists today, but makes only hydraulic and related engineering components. Unlike all other K&E rules, this model lacks parts/serial numbers, consistent with its basic design features. The cursor is also considerably larger, and it lacks the internal ruler under the slider. Unfortunately, the bamboo is almost completely covered by celluloid, with the exception of the exposed ends of the rule. The rule and case are also both in very good condition. clearly, this specimen represents the very beginning of the shift in HO/Geotec labels. a fascinating specimen, and a nice addition to the my K&E family. I've never seen the insides of this type of case in such amazingly good condition. Superficially, the patina on this specimen is clearly much whiter, although it has some red ink discolourations along the inch ruler edge. I am working on an upcoming Slide Rules in Canada page that will feature more information about the Hughes Owens company and its products, including the various catalogs in my collection. The rule has a good solid feel and slides very easily, although I think I still prefer the mahogany look of the K&E models.
Eric's Keuffel & Esser Slide Rules. This particular rule was in pretty bad shape when I got it, but it cleaned up very nicely as you can see on the high resolution scans. A centimeter ruler adorns the slanted edge and a standard cheat sheet is on the back. Dating with a purpose. Probably my favourite slide rule manufacturer, K&E was the dominant slide rule maker in the US. Their rules featured mahogany cores with celluloid facings, and have one of the nicest "feels" among slide rules, if you know what I mean. The case has the smart adaptation of a little clear plastic window under the flap in which to put your vital statistics. The leather case for this rule is also the high quality leather type, and it has aged to a nicely satisfying rich brown colour. Interestingly, it's the only time I've seen such similar offerings from these two premiere slide rule companies. The cheat sheet on the back is the same in content as the other two, but in better shape, and with a change to a more modern looking font. Odd that they are now worth considerably more than the actual rule. Reflecting their Japanese origin, these rules were often made of bamboo with celluloid facings, which worked out very well since bamboo is naturally self-lubricating and withstands changes in temperature and humidity better than other types of wood. If anyone has a better guess, please let me know. Quite a nice rule, but I guess there wasn't much of a market for this type of medium-grade high-end rule, given all the versalogs and versatrigs out there. They also made a large range of drafting and related products, and even had offices here in Montreal.
Given their extensive range of products, it is not surprising to see a number of specialized rules out there as well. Like its contemporary non-vector siblings, it has undergone a considerable re-adjustment in the location of the log-log scales, and the inverted DI scale has returned. You'll notice that they clearly seem to have dropped the N designation by this point. Otherwise, not much changed from this immediate precursor. Dating other people movie. Additional dating information has been obtained from a variety of sources, with special thanks to Ed Chamberlain for his excellent set of K&E dating curves based on K&E serial numbers. as you can see from the high resolution scans, it's taken a pretty good beating and the stitching has come loose is one spot. All the other scales and the K&E labels and patent dates have stayed the same. That particular rule has taken quite a beating though. Instead of the typical leather/cardboard cases shown with the other rules on this page, this one has the older hard textured particle-board type case with leather closing flaps bolted on. I've also managed to pick up a Hemmi slide rule magnifier for this type of cursor - it looks a bit silly on top, but zooms in quite nicely. But the leather is beautifully worn and fits very snugly around the rule, like a glove. Interestingly, the instruction manual has both the Hughes Owens name and Geotec logo shown on the cover. More information about this find will be presented shortly on my upcoming Slide Rules in Canada page. the older frameless design was prone to breaking. Like all the older model rules, the K&E product information and patent dates are on the face of the rule. They have also dropped the DI scale on the back, for some reason. The belt clip is still intact, though. Over the course of production, they carried an extensive range of slide rule models, although they frequently changed their model numbering schemes in the last couple of decades of slide rule production, confusing matters considerably for collectors