editorial new members - slide rulesliderules.lovett.com/articles/skid/ss20.pdf · sprocket sizes,...
TRANSCRIPT
ISSN 1466-3570
June 2005 No. 20
NEWSLETTER of the UK SLIDE RULE CIRCLEEditor: Colin Barnes, 189 Mildenhall Road, Fordham, Ely, Cambs. CB7 5NW England
Tel: 01638 720317 e-mail: [email protected]
Editorial
Like me you probably find type errorsin papers and magazines somewhatirritating so you can imagine howgalling it is for me to be guilty of thesame mistakes. SS 19 contained anumber (some of which were correctedduring printing) that escaped me despitereading through at least three times.My particular apologies to “High” Tidy.I have no excuses other than advancingyears and a lack of concentration whenproof reading. Spell-checks are greatbut they are not the answer. While on the subject of spell-checkers,a friend unsurprisingly found the nameMandy Morton underlined in red. Thealternative suggested by the spell-checkwas “Mangy Moron” which heunkindly felt was more apt!
I received word at the beginning of theyear from Jennifer Dennis that herhusband, John, had become severelydisabled and as a consequence has hadto relinquish his membership of theUKSRC and Oughtred Society. Sadnews indeed.
I feel I cannot resist the temptation tocomment on an editorial in the DailyTelegraph of March 21 in response to asurvey undertaken by MunichUniversity:-“The electronically challenged willchortle at the news that computers maycontribute nothing to pupils skills inmaths and literacy. But in fact thestudy published today by the RoyalEconomic Society is more serious thanthat. It suggests that the vast sums ofmoney spent on equipping state schoolswith computers - £2.5 billion so far,with £1.5 billion more promised in lastweek’s Budget – are largely a waste ofmoney. …. Moreover, familiarity with
them at work has no more effect onemployability or earning power thanbeing able to use a telephone or apencil”For those that are familiar with thephrase…. little Audrey laughed andlaughed.
New Members
T. Gordon Roberts27 Springdale Court
MickleoverDerby DE3 9SW
01332 [email protected]
Chris Leech70 Biddulph Road
CongletonCheshire CW12 3LG
01260 [email protected]
Jonathan Denmee12 Tierney Court
Canning RoadEast Croydon
Surrey CR0 6QA0208 6545653
Peter FoxGreenhough House
UppertownBonsall
Derbys. DE4 2AW01629 824921
How to Use a Slide Rule as aBicycle Gear Chart
[The following was spotted by John Seago andreproduced here as found on thewebsite;http://www.cs.uwaterloo.ca/~arpepper/Cycling/slide_rule.html]
Anyone who has an old dusty slide rule lyingaround that they are not sure how to usemay be interested to know that sliderules are great for doing gearcalculations too. Seriously.
1©2005 The UK Slide Rule Circle and the contributors
Skid Stick Issue 20June 2005
Let F be front chainwheel size, that is, numberof teeth. Let R be rear sprocket size, that is,number of teeth. Gear ratio measurement values discussed heremust be those obtained by using a formula ofthe form W*F/R.[*] In the case of "gear inch"measurements, W is simply the wheel diameterin inches. In the case of "metres ofdevelopment", W is PI multiplied by the wheeldiameter in metres. Etc. So, the method is simply to determine W, andthen: Line a given value F, a chainwheel size, on thescale CI(C inverse), with W on the D scale.Values on the D scale now correspond tosprocket sizes, which line up with theircorresponding ratio measurement on the CIscale. [*]Gear ratios can be measured using the formW*R/F. An example of this might bemeasuring them by determining the cadencetheoretically necessary to maintain 20mph ineach particular gear. This probably isn'tparticularly useful, not even for==>tandems<==. You can also use the C and D scales. Line upW on the C scale with R on the D scale. Now,each chain wheel size on the D scale lines upwith its corresponding gear ratio value on the Cscale. While this has the virtue of avoiding thedifficult-to-use CI scale, which necessitatesusing the cursor, it has the disadvantage thatyou cannot read off the values for eightsprockets at a time without moving the slide, ascan be done by using the CI scale. Sheldon Brown of Newtonville Massachusetts([email protected]) adds the followingobservations: From aol.com!CaptBike Sun Oct 16 14:19:06 1994From: [email protected]: [email protected]: Slide rules & ==>tandems<==
To find sprocket combinationsthat will yield a desired gearvalue, set the desired gear (Cscale) above the wheel size (Dscale) Any chainwheel value onthe C scale will be right overthe rear sprocket value on theD scale that will yield thedesired gear.
On further consideration, theprevious message on slide rulesis correct for solos, but for==>tandem<== applications you
should use the A & B scalesinstead of C & D. The A & Bscales have a whole cycle forthe captain, plus another forthe stoker!Using the C & D scales as Iindicated doesn't work so wellfor gears over 100", a seriousproblem for those of us whoride twofers. From “The Guardian Weekend”, 5 February2005. Pyrgic* Puzzles, Question 5:
“I thought that the pub I had heard of in LooseChippings was named after a piece of pre-calculator-y equipment, but the sign, when Isaw it, displayed a cunning old fox salivatingover a chicken. Explain”.
Answer: It was a sly-drool!*what is a pyrgic?
BookwormNew Mathematical Pastimes, P. A. MacMahon, reprint edited by John Sharpwith introduction by Paul Garcia. QED Books & Software, Pentagon Place, 195BBerkhamstead Road, Chesham, Bucks., HP5 3APBook: mono paperback £15.00CD: full colour CD £12.00Book and CD £21.00www.mathsite.co.uk
Major Percy Alexander MacMahon isone of the 19th century’s forgottenmathematical heroes. He was the son of asoldier, and began a military career at the ageof 16, with no thought of becoming amathematician. An illness contracted whilstserving on the North Western Frontier of theBritish Indian Empire in 1877 forced him togive up active service. The only avenue opento him was the Advanced Class in Mathematicsat the Royal Artillery College, a courseshunned by most officers because it was toomuch like school, and because it offered nochance for war and glory.
MacMahon blossomed in this class,and was taken under the wing of the professor,Alfred George Greenhill, who nurtured histalent for computation. Thus MacMahon
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became an instructor at the Royal MilitaryAcademy, and worked with Greenhill onproblems in ballistics.
In 1884 he made an importantdiscovery in invariant theory, a major area ofresearch in the 19th century in Britain andGermany. This brought him to the notice ofthe wider mathematical community, and withinten years he was elected President of theLondon Mathematical Society. He was alsoelected to the Royal Society, the RoyalAstronomical Society, served in the BritishAssociation for the Advancement of Scienceand received three medals and four honorarydoctorates during his lifetime.
MacMahon published NewMathematical Pastimes in 1921. Up to thattime, he had published four papers onrecreational topics: On play a outrance [1889],Weighing by a series of weights [1890], On thethirty cubes constructed with six colouredsquares [1893], and Magic squares and otherproblems upon a chess board [1902].
This is a very small quantity of work,compared to the 91 papers on invariant theory,partition theory and combinatory analysispublished by MacMahon up to the same time(summarised in a classic two volume work,Combinatory Analysis, published by CUP in1915 and 1916, and still cited today bymathematicians and scientists working in awide variety of fields). Thus the casualobserver may have missed MacMahon¹scontribution to recreational mathematics. It hasnevertheless had a widespread and persistentinfluence.
MacMahon himself obtained threepatents for puzzles, in 1892 and 1893, showingthat he had been enthusiastic about edge-matching puzzles, and doing original work inthe field, for many years prior to thepublication of New Mathematical Pastimes. One of these patents, for a cube puzzle basedon the work in the 1893 paper, was turned intoa commercial product, called Mayblox, sold intoy-shops in the early 20th century.
The ideas in two of the patents, andthe 1893 paper mentioned above, formed thecore of New Mathematical Pastimes.
The book was important for twoprincipal reasons. Unlike conventionalrecreational mathematics books, that wereessentially collections of puzzles and theirsolutions, MacMahon set out to demonstratethe principles by which an interested reader,with some work and thought, could create hisor her own amusements. It also contained acompletely original approach to visual puzzles,
where edge matching could be forced byaltering the profiles of the edges, a processdescribed in Part II of the book.
The results of these transformationsare remarkably similar to work produced byMaurits Escher, and predate him by a decadeand a half.
The reason for producing this reprintof New Mathematical Pastimes in the year ofMacMahon¹s 150th birthday is to be found inthe preface of the book. MacMahon wrote: “Ithas not been possible to produce the book incolour, and as the author has himself invariablyinvestigated the sets in colour he must confessto a feeling of disappointment at theappearance of the pages.” This lament isfollowed by a little quote:
In colours fresh, originally bright, Preserve its portrait and report its fate!The Complaint
I hope that MacMahon wouldappreciate the appearance of these electronicpages, and that a new generation might findinspiration and amusement in the puzzles thatwere an entirely original invention of thisremarkable mathematician.
The CD is the recommended versionunless you like to have a copy for yourbookshelf or want to read when you haven’t aPC to hand.
Paul Garcia
The Oughtred Society Slide Rule ReferenceManual is now available.
ThisnewManual isthe first in manyyears and is theonlyManual of itskind. Itcontains theusualinstructions on how to use a slide rule, alongwith chapters on additional subjects such as:
Slide Rules on the Internet ---general information, organizations,dealers, collectors, museums,manufacturers
Cleaning and Caring for YourSlide Rule --- rules, cursors, endbraces, cases
Collecting Slide Rules --- why,what, value
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Skid Stick Issue 20June 2005
Major Companies and Some ofTheir Common Models --- USA,Germany, Japan, England, France,Denmark
Common Types of Slide Rules ---types, materials, scale arrangements
Less Common Types of Slide Rulesand the Quest for GreaterPrecision --- linear, circular,cylindrical, 50 cm, collectors'favourites
Tricks and Time Savers Advanced Slide Rule Features ---
gauge marks, multi-line cursors,colour coding
Slide Rules for SpecialApplications --- chemistry,surveying, electronics, etc.
History of the Slide Rule --- beforethe slide rule, chronology, its lastcentury
List of 24 Common Slide RuleScales and their Functions
What is a Slide Rule --- definition,unique characteristics, manufacture,what they do, what they have done
How a Slide Rule Works ---logarithms, a couple of strange terms,starting point, numbers less than one
The Manual is 102 pages of information, plusintroductory pages, Table of Contents andIndex. It is letter size, 8½” X 11” (same sizeas the Journal of The Oughtred Society). Itis perfect bound (like a quality magazine ...National Geographic, for example), with ahigh quality heavy cover in colour. It featuresmore than 100 colour photos, almost all ofwhich are slide rules.
Detailed information appears on the OughtredSociety’s website:
Price: $35.00 + $9.00 postage, (UK)
Payment may be made by check or moneyorder payable to The Oughtred Society. Mail your check or money order to : Ted Hume The Oughtred Society P.O. Box 63021 San Angelo TX 76906You may pay for your Manual with your creditcard via PayPal on the Oughtred Society website ( www.oughtred.org )
Description of the new Sliding Rule ofInvolution. Invented by Dr. Roget, secretary
to the Royal Society with instructions for usingit. 1828.Reprint: UKSRC, 12pp booklet. Price £1.00inc. postage (UK)
Slide Rule modified by M. Mannheim –Directions. Transcribed and reset from asingle folded sheet. c.1900.UKSRC Reprint, 8pp. Price £0.75p inc.postage (UK)
Musings 20Peter Hopp
Derek Slater’s original intriguingquestion in SS18, “Which twelve slide ruleswould you keep?” followed by GeraldStancey’s enjoyable list and explanation inSS19 have had me Musing furiously. Itbrought to mind all sorts of parameterspreviously considered: general or specialist,old or new, value, rarity, particular pleasure tothe individual collector, plus a whole host ofother things imponderable. After muchthought, my list:- A Fuller (my favourite)- A Thacher (wishful thinking)- A Unique (why not?)- At least one watch pocket slide rule,
(Fowler, Calculigraphe, Lords, oh dear,how difficult)
- An Otis-King (another helical)- A fancy Faber-Castell (2/82, or something
else with lots of scales)- A Coggeshall (2-foot,2-fold example)- An “Everard” alcohol rule (example of
early design)- A Thornton AD050 (most common slide
rule on earth!)- A Rietz or Mannheim rule (typical general
purpose rule)- A 20” rule (example of the type)- An F-C TR (with electronic calculator) for
sheer idiosyncrasy of the design.Having produced this list I can think of at leastanother half-dozen which should be includedfor any number of reasons:- A Calculex (different design, surprisingly
successful, or was it purely ornamental?- Something with an Addiator (pre-
calculator daftness)- A projection slide rule- A circular slide rule- A large teaching rule- Something really weird, like my German
actuarial slide rule4
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Skid Stick Issue 20June 2005
I can see where Cecil Clutton comesfrom. Having a “Bijou” representativecollection is very neat, and it really would be amajor discipline to keep to 12. For me, sellingone when you buy the 13th would be likepulling teeth! I can feel myself beginning towriggle – does 12 represent something asdiverse as slide rules? Of course it does, anynumber can be selected and the representationis simply different, but still representative. It’sjust that my “Squirrel Instinct” (also previouslydescribed as anal retention) simply revolts overhaving to get down to such a selection. This isa really fascinating question which I am surewill come back to mind several times in thenext months. I hope that many other peopletake the opportunity to produce their lists so wecan see what, and maybe why, they haveselected their list of rules.
My 2004 reading included some of thebest books I have ever read, and some that Iwish I had access to previously. Of particularnote were “Eats, Shoots & Leaves” as theperfect un-pompous idiots guide to punctuation(watch me continue to get it wrong!);“Forgotten Voices of the Great War” as one ofthe best books on the Great War; the absolutelyincredible “The Curious Incident of the Dog inthe Night-time”; Bill Bryson’s “A ShortHistory of Nearly Everything”, and the HenryPetroski pair “The Evolution of Useful Things”and “To Engineer is Human”. This last bookshould be essential reading on all Engineeringcourses. Those of you who have looked at the2nd E-Musing on the UKSRC web site will haveseen that I was particularly inspired with somearticles from its Bibliography. While choosingthese books I found myself further musing onthe prophecy (yet again) of the paperless book.I am sure that books will be with us for a longtime yet, and hopefully will not be “overtakenby technology” in my lifetime. We werepromised the “paperless” office many timesover the last decades. Like the paperless toilet, Ibelieve both these ideas are impractical. I findthat trying to read things off the computer screenis nothing like as much fun – or as easy - asbeing horizontal on the sofa, in bed, or curled ina chair. Am I the only one to be particularlyinspired by some of last year’s books? Or is itjust simply that in the welter of new publicationssome must be good!
My image collecting has taken a majorstep forward – I now have a couple of videoclips (with sound) involving people and sliderules. These cannot (obviously) be included inSkid Stick (“Thank Goodness” I hear the cry)however they are very entertaining in small
doses (very small!) and yet another way ofrecording a disappearing capability.
I have a very soft spot for weirdpictures of people and slide rules, and there canbe fewer more surreal than the one below! Itcomes from the University of Michigancentenary web site, and shows some members ofthe “Mimes”, an all-male “operatic” company,in about 1913 “satirising” life at U-M. Looksmore like some strange gravedigger’sconvention, and the giant slide rule looks likethe side of a weird coffin with a window in it –or is it me who has the strange bent?
Is this a Slide Rule?Colin Barnes
The picture below came to me from aDutch friend of Richard Rigby’s who took itthrough the shop window of an “antique shop”in Antwerp, Belgium.
We are probably all familiar with theload adjusting slide rules designed for aircraftand, from my limited knowledge of shipdesign, I surmised that this was the marineequivalent. It was most satisfying to find laterthat my idea was correct.
I wrote to fellow slide rulers inBelgium and, after my letter had gone astrayvia Belfast, I received a reply from WillyRobbrect who had also seen this instrumentand told me it was in the shop of Van de Valk,Oude Koornmarkt 50, 2000 Antwerp. A letter
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to the shop brought a response from Lew vander Valk by e-mail with further pictures andthe following information.
The instrument is indeed a shiploading calculator which came from a shipbreaker’s yard. Inside the lid of the case is theoutline of the ship showing the differentcompartments. The vessel would appear to befairly modern as it is shown with a bulbousbow and was probably designed as a bulkcarrier (grain). Her name was the “Kristina”,registered Copenhagen and built in Norway byHorten Verft.
The case is approximately 125cm x45cm x 18cm and has one drawer which isshown almost fully open in the illustrationbelow.
The drawer contains a number ofscales as does the top panel under the cover,both of which appear to have some form ofcursor or cursors. I assume that each scalerepresents a compartment, that the weight andcentre of gravity of which is integrated with allother compartments to ascertain the totalloading and centre of gravity of the shipincluding fuel, ballast etc. These figureprovide the final draft and trim when the centreof flotation is known. I have not seen aninstrument like this before, however, a simplerdisc version was described in my article inGazette 3, 2002 for use on WWII Libertyships.
The plate inside the lid reads: “Restricted use of this instrument”
This instrument is only to be used when the distribution of cargo or ballast over the ship’s length is reasonably even without any concen-tration and with empty lengths within the cargo compartments not exceeding 10 metres at full draught, 15 metres at ballast draught.
Is this a slide rule? Has anyone experience orknowledge of a similar instrument? Anyfurther information would be very welcome.
Dr. Roget’s Sliding RuleDieter von Jezierski
I was visiting the Technisches
Museum in Vienna looking for(unsuccessfully) the Sedlacek demonstrationslide rule1. I did find an A. W. Faberclassroom slide rule from 1901 (two metreslong) and other interesting items includingRoget’s “Slide Rule of Involution”.
This rule has the registration number7384 and was included in the Museum’sinventory c.18292. The rule is made ofboxwood, 20¾" long x 1" x 5/16" with blackimprinted scales. Under the slide is the imprint“Cary, London, Dr. Roget Sec.” A similarslide rule is to be found in Baxendall’scatalogue of slide rules, Science Museum,London.
I was able obtain a copy of theinstructions for this rule (see Bookworm)which includes the following description.
1 This demonstration rule was devised about 1850 by Prof.Sedlacek and used by his colleague Schultz von Straßnitzkiat the Polytechnical Institute of Vienna. It was 260 cmlong, 30 cm wide and 5 cm thick. It had no cursor but hadthree slides with 12 logarithmic scales. (See “Slide Rules –A Journey Through Three Centuries” p.85, Astragal Press,Dieter von Jezierski). 2 The Technisches Museum in Vienna was founded in1908 and inaugurated in 1918 but its origins go back to1807, 1815 and 1817 when several collections from thePolytechnisches Institut were amalgamated into the newbuilding in 1918. It was usual for such slide rulespecimens to be sent to Technical Institutes and to offerthem to experts and professors of mathematics on thecontinent in order to promote their use. Dr. Roget’s rulewas typical of this “promotion” which did not achieve itsaim. It would be 75 years before Roget’s log-log scalesbecame more significant.
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“By employing a different mode ofgraduation, Dr. Roget has contrived a Sliding-rule which exhibits, at one view, all the powersand roots of any given number.” Later, “Thetwo lines, which are graduated on the ruleitself, and between which the slider passes,(the upper line being a continuation of thelower one), is a scale of the powers ofnumbers. It begins on the left end of the lowerline, where the first division, that is numbered,is marked 1.003; the next is 1.004, and so on,increasing as we follow them left to right, untilwe arrive at the division 1.2, which is the lastnumber marked on the lower scale. Thegraduation is continued from the left end of theupper scale, where we next meet with thenumber 1.3; to which succeed 1.4, 1.5, 1.6, &c.up to 2. Then follows a series of wholenumbers, 3, 4, 5, &c., 10, 20, 30, &c., 100,1000, 10,000, &c. to one million (marked 1m),and so on, according to the successive powersof 10, as far as 1010 (or 10,000,000,000),where the scale terminates”.
Dr. Peter Mark Roget will be bestremembered for his Thesaurus published in1852, however it is probably less well knownthat he was secretary of the Royal Society(1827-49) and an original member of theSenate of London University. Roget was bornin London in 1779 and studied medicine atEdinburgh becoming a physician to theManchester Infirmary in 1804. He becamephysician to the Northern Dispensary, Londonin 1808 and Fullerton professor of physiologyat the Royal Institution. 1833-36.
My thanks to the Editor for hisbiographical information on Dr. Roget.
Another Mystery Object
Front
BackWhat is it?The front says:
A.A.PERCY’SPATENT
GLASGOWBREVETTE S.G.D.G
The circular hard-brass disc with its variouscut-outs is 1” diameter and 0.05mm thick..The plungers are spring loaded and work the“ears” on the bottom (right above).It came with the ears hooked into the edges onthe back of a Hemmi slide rule.
Again a copy of Podmore’s “The Slide Rulefor Sea and Air Navigation” is offered as aprize to the first correct, best or original guess.Answers to Peter Hopp whose decision will befinal.
Feedback
Twaddells
Paul Crowther’s reference to DegreesTwaddell (SS 19) reminded me of the first timeI met this seemingly archaic unit. I was
working for a company that made synthetictanning agents; these were aqueous solutions ofresins. The final stage in the process was todilute them to strength and the measure ofstrength used was Degrees Twaddell. Theamount of water to be added to get the correctstrength was easily calculated as follows:
Water needed = original volume ofwater multiplied by the difference in Twaddellsdivided by the original Twaddell.
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Dieter von JezierskiDr. Roget’s Slide Rule
Skid Stick Issue 20June 2005
As always a worked example clarifiesa complicated sentence.
Original Twaddell = TwDesired Twaddell = Tw'Original volume = V any unitsVolume of water to be added to dilute
to Tw' Degrees Twaddell
= V(Tw - Tw' )
TwThis is a very easy calculation and
shows that the inventor of this system ofspecific gravity measurement was a practicalman who wanted to make life easy for theprocess personnel.
Gerald Stancey
Hans Bethe
FrancisWells picked upand has forwardedthe obituary noticeof Hans Bethe, thenuclear physist,taken from TheEconomist ofMarch 19, 2005.Bethe was born inStrasbourg in 1906and studied inMunich, Rome and
Cambridge before emigrating to the US andCornell University where he remained exceptfor his time in New Mexico on the ManhattanProject.
Bethe continued publishing papers,mostly on black holes and supernovae, wellinto his 90s, relying to the end on an old sliderule to make his calculations. It was, he said,good enough.
This Book Belongs to …
The following comes from the “bookplate” ofthe handwritten manuscript of an unknownbook on mathematical instruments of about1835, courtesy of Derek Slater.
The handwritten text reads:
This Bookbelongs to
Charles Chowler
If thou art borrowed by a friendRight welcome shall he be
To read, to copy – not to lendbut to return to me.
Not that imparted knowledge dothdiminish learning’s store
But books, I find if often lent,Return to me no more.
So the ReaderRead slowly – pause frequently –
think seriously – keep cleanly -return duly, with the corners of
the leaves not turned down.
Web SitesTom Martin
I have been given these in relation to breweryhistory and slide rule. www.ingenious.org.uk This is a collection ofimages from the Science Museum etc. “SlideRule” gives 72 different images. www.scholar.google.com gives titles andsometimes text to articles and books. “SlideRule” gave 17,200 references in 0.02secs. Itkicks off with highly specialist papers. Themore one defines slide rule the more the wordsare separated. “Customs and Excise SlideRule” gave one hit to someone called Colin
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Barnes, the rest were rules and regulations oreconomic slide type refs.
Fermat’s Last TheoremPeter Hopp
Simon Singh’s book “Fermat’s LastTheorem” is a fascinating and very readabletrip through the search for a solution starting in1637 (just after the invention of the slide ruleby Oughtred) through to the final completionof the solution by Andrew Wiles in 1994, (wayafter slide rules had ceased to be generallyused). I would recommend it even for the non-mathematically inclined. When he gets to thesituation the solution hunters’ foundthemselves in the 1930’s he describes howmathematicians had exhausted all theirtechniques and were looking for a new tool tohelp continue the search for a solution. Hefollows this with a comment (p166) “TheSecond World War was to provide just whatwas required – the greatest leap in calculatingpower since the invention of the slide-rule[sic]”.
Two things occurred to me:- I have never thought of the slide rule
as being as great a leap forward as thecomputer in providing mathematical“power”, but I guess it really musthave been so.
- Neither slide rule nor computerfeatured in the search for a solution.Wiles in particular believed in simplepencil and paper! Strange or what?
Cursor CoverHugh Tidy
An afternoon in Reigate whilst ferrying the“boss” I bought a very nice Faber 378 with amost interesting metal cover on the cursor.This cover is marked “Cover for slide rulecursor. Patent Applied For. E&S.B.W.Ltd –L”. Shaped from a piece of metal that clipsover the cursor it is presumably designed to
protect the glass. Has anyone seen a similarcover and who were E&S.B.W.Ltd, from the“Ltd” one would assume it is of British origin?The idea that these were made in any greatquantity seems unlikely, just imagine thenumber of various sizes required to cover alleventualities!
“Quarter Squares”Mike Williams
I have been delving and foundsomething I maybe should have known buthave never seen before...Do you know about "Quarter Squares"? As in:to multiply 27 by 16 by adding andsubtracting..... 27+16 is 43 and the QS of 43 is 462 fromtables (the odd quarter is left out from 462.25) 27-16 is 11 and the QS of 11 is 30 from tables (121 /4 less the quarter) Subtract 30 from 462 and get 432 which is ofcourse the product of 27 and 16. Just add onceand subtract twice.
I found all this in a smallChamber’s Trig Tables (seven figs) booklet, a1959 reprint. It is not in the biggerCollege Edition. The tables go from 1 to2220. It is based on a bit of neat algebra linkedto the "2ab" in the square of a plus b.
This was strange and new to me andthen by chance I found the article in JOS. Vol.11, No. 2 (2002) on the same subject whichcovers the subject in some detail. You mightlike to check this out.
It’s a Slide Rule but not as weknow it
The picture below has been suppliedby John Bolton and comes from The Autocarof May 1st, 1942. There is no indication of sizebut on the face of it, it looks massive. Perhapsthe name of the company provides a clue,“Newman Motors”. Did they make electricmotors? Probably this instrument is quitesmall and built into a miniature of one of theirproducts as a promotional item. Designed tocalculate pulley sizes and speeds (for electricmotors?) this seems likely.
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A circular slide rule made of millboarddesigned to simplify calculations of pulleysizes and speeds. It costs 2s. 6d. (while stockslast) from the inventors, Newman Motors, ofYate, Bristol.
Origami
In SS 18 we featured an apparentlyimpossible shape made from a single sheet offolded paper. Now we learn that Dr. EricDemaine, an assistant professor of computerscience at M.I.T. is a leading authority in theemerging field of origami mathematics, thestudy of what can be done with a folded sheetof paper. You might like to look at his website: http://theory.ics.mit.edu/-edemaine/foldcut/examples/
This information, gleaned from theNew York Times, led me to wonder how Dr.Demaine got started on this path in view of thelegend that is (was) carried on official USGovernment paperwork with the direconsequences that would result from ignoringthe exhortation –
Do not Fold, Spindle or Mutilate
OS Swap Sheet
You are cordially invited toparticipate in the Oughtred Society Swap SheetOnline, which is a listing of slide rules andrelated items for sale and for trade. TheOughtred Society Swap Sheet has beenprepared annually in printed form for manyyears with copies being mailed to OSMembers.
As of February, 2005, the Swap Sheetwill be a continuous feature of the OS websiteand updated monthly:
<www.oughtred.org>[Access to the swap sheet is restricted bypassword to OS Members and members of theUKSRC, Kring, RST etc. For your passwordplease write or email me. Ed.]
Announcing : The OughtredSociety Award and Call
for Nominations
Otto E. van PoeljeProject Chair, The Oughtred Society Award
One of the diverse new initiatives of theOughtred Society is the institution ofthe “Oughtred Society Award”.
This award will be presented each year tosomeone, within or outside the OughtredSociety, who has made outstandingcontributions to the community involved withslide rules and historical calculatinginstruments at large.These contributions may be within our owncommunity, for example publications in theJournal of the Oughtred Society or otherspecialized papers, writing of books, orstimulating activities like organizing meetings,expositions, websites or any othercommunications media. Also publicityactivities toward the general public areconsidered as important contributions.The award will recognize such outstandingachievements, while at the same timeencouraging our whole community to excel,and establishing the Oughtred Society as thepre-eminent organization for collectors andconnoisseurs of slide rules and historicalcalculating instruments.
For the initial phase of the Oughtred SocietyAward, the Board of Directors of the OughtredSociety appointed at their Meeting of January23, 2005, Otto E. van Poelje as ProjectChairman, and Robert Otnes and Ted Hume asmembers of the Award Committee, which latermay be extended to five members.
The Award Committee invites members of theOughtred Society to propose nominations forthis new Oughtred Society Award.Please send your nomination in writing or byemail, including your considerations for thenomination, to:
Otto van PoeljeSnelliuslaan 25
NL-1222-TB HilversumThe Netherlands
email: [email protected]
The Award Committee will consider allnominations received before September 1,2005, in their choice for the Oughtred SocietyAward.
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Skid Stick Issue 20June 2005
The presentation of the first Award will beorganized before the end of the year 2005.
Help!
Can anyone help with moreinformation on the following slide rule andothers by this maker? The rule is of all metalconstruction with what appears to be a bronzelacquer finish. It is 10½ inches long and with astock width of 24mm, is of the Mannheim typewith scales ins/A/B, C/D/cms//SLT. The wellof the stock is marked: J. B. Stoellner, Nuernburg (Germany) No300 DR PAT 39777 DR PAT 412597Unfortunately the cursor is missing otherwisethe rule is in good condition. The case roundedsomething like the early Fabers and the datasheet is all in English.
What might the date of manufacturebe? The patent numbers wouldsuggest after 1933.
What sort of cursor would it havehad? The quality might suggestchromed metal and glass
Does anyone have such a cursor thatthey may might sell tome or swap fora Faber-Castell of which I haveseveral?
Does anyone have one of these orsimilar by this maker?
Brian [email protected]
[Initial enquiries into this company haveproduced the following: Ed.]
from Karl Kleine and Dieter von Jezierski:
DRP 397777 is a slide rule patent titled“Rechenstab” granted to J.B.Soellner Nahf.Reißzeugfabrik AG, Nürnberg, application date19 April, 1923, issued 7 July, 1924. Thesubject of the patent is the number and form ofgrooves for the slide.DRP 412594 is a supplement to the patent DRP412020 and relates to the addition of aprotective coating on metal surfaces called“Elektronmetall”. Elektronmetall is an alloy ofmagnesium with a small amount of aluminiumand/or zinc. The Griesheim-Electron chemicalcompany first applied to patent this material in1909. It later became popular for aircraftengines and components due to its low weight.DRP 397777 has the following equivalents;GB 214604, France 582237 and Austria100527.
DRP 412020 has the following; GB 218619and US 1642309.DRP 412597 we have; French 585768 andSwiss 110753.
from Peter Hopp who originally contactedDieter:
I have looked through my book and its updateddata (as yet unpublished) and noted that I hadrecorded DRP 397777 against Reiss as makereven though the name of the patentee is givenas Soellner Nachf Soellner. In my updatedinformation on Reiss I note “History: 1923patent. Still making a range of slide rules aslate as 1970, the later identified from ConciseEncyclopedia of Mathematics from VanNostrand Rheinhold c.1971. See alsoEICHMULLER and BAYERISCHEREISSZEUGFABRIK A.G. both of Nuremberg,who preceded this company name but noapparent links. Joined MEISSNER to becomeV.E.B., not known when”.There is more information in GeorgSchreiber’s paper “Slide Rules from Dresdenand Bad Liebenwerda” presented at Greifswald(Eng. translation, UKSRC, 2001) regardingReiss, Meissner, V.E.B and others, not yetincluded in my update.Eichmuller and Bayerisch Reisszeugfabrik alsomade metal slide rules (the latter with doubletongue slides) as indicated in the Br.Intelligence Objective subcommittee report of1946. (John Knott, German Slide RuleManufacture in 1946, Proceedings of theInternational Meeting 1999)A newish “aluminium” Ecobra slide rule in mycollection also has a double tongue slide butthere is no mention of a patent.
Tachymetric Slide RulesRecently, I was asked to write an
article on Tachymetric Slide Rules for “DeHollandse Cirkel”, the journal of the DutchSociety for the History of Geodesy.
During my research, I collected thetypes of tachymetric slide rules that have beendesigned and produced by some majormanufacturers, see table below. For the UKregion I received gratefully a lot of input fromPeter Hopp and Colin Barnes, but after somediscussion we concluded that in the UK veryfew tachymetric slide rules must have beenproduced.
The question to the UKSRCcommunity is: did we miss some brands or arethere indeed very few tachymetric slide rules inthe UK, and if so: what might have been the
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Skid Stick Issue 20June 2005
reason? Was it a different practice andapproach to distance measurements by UKsurveyors, or might there have been a differentreason?
Tachymetric slide rules (also called“tacheometric” or “Stadia”) can be recognizedby their specialized scales for the reduction ofa measured distance to the horizontal and thevertical component:
cos2 , sin.cos, or ½ sin (2a).In the following table, only
tachymetric slide rules are listed. Othergeodetic rules have been left out. There musthave been many more tachymetric types.
Table of known Tachymetric Slide Rules
Maker TypeDIWA 231, 241
D&P/Aristo 23, 24, 44, 48, 958, 0958,680
Faber-Castell 1/38, 111/38, 4/38, 67/38Nestler 9a, 28, 280, 281, 285,286Reiss 1145Stanley Fuller Bakewell Type 3Morin unnamedGraphoplex 630Tavernier-Gravet
Topographie
Sun - Hemmi 2690,269Concise Stadia ComputerMatthijssen unnamedKueffel & Esser
1749, 1749-3, 4125, 4100,N-4100, 4101, N-4101, 4105, 4143(681486)
Kern (Aarau) unnamedLoga Topo 6400
Otto van [email protected]
Farmar’s Spirit Rules
I am planning an article on these rulesfor inclusion in a future Gazette and would liketo have information from any readers who cansupply dates, addresses and any otherinformation on the Farmar’s rule.
Peter. [email protected]
‘Local’ Spring MeetingGeddingtonGerald Stancey
The morning of Sunday 15 May was abeautiful spring day. The drive to Geddingtonwas enjoyable – little traffic and thecountryside looking its best. The spring
meeting had to be good and indeed it was.Seven members:Colin Barnes Rod LovettBrian Lloyd Mick TaylorTom Martin Peter HoppGerald Stanceypresented themselves at the residence of Derekand Mary Slater in rural Northamptonshire.
As usual conversations that had beencut short at the last meeting resumed as if timehad not passed. The theme of the meeting waspromotional rules, that is rules that were givenby companies as advertising items to favouredcustomers. The range of industries thatparticipated in this activity was amazing,showing how widespread the use of the sliderule was as a primary calculating tool for thenumerate.
Most of the rules were standard sixinch Mannheim or Reitz but a few werespecials designed for a particular industry. Forexample Shell/BP gave a rule that had scalesfor a calculation involving CO2 but I wasrelieved to see that it also carried C and Dscales. Circular slide rules were very wellrepresented. Some of them were mounted on arectangular base about the size of a playingcard the back of which carried “useful” data. Iwondered if there could still be a market forthis type of give-away-goodie as it would beboth useful and unique.
Many of the rules did not carry amaker’s name but it was obvious that Blundell-Harling were heavily involved in this business.
After an excellent lunch came theformal part of the meeting. I decided it wouldbe prudent to show consideration for others bysitting on an upright chair rather than use theinviting looking sofas. The truth is that Iwould have fallen asleep – always the sign of agood lunch. It was noted that at least twomembers were so afflicted for short periods oftime – no names no pack drill. The main itemfor discussion was the International Meetingthis October.
Time advanced quickly and soon itwas time for us to leave but not before beingwell refreshed with tea and biscuits. We had awonderful day and all the attendees would liketo thank Derek and Mary for their hospitality.
Weather Forecaster
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Skid Stick Issue 20June 2005
In SS 18 we reported on the pocketweather forecaster originally made by Negretti& Zambra and subsequently made by a numberof companies. A more detailed article on thisinstrument and the history of Negretti &Zambra has been prepared by Michael Isaacsfor inclusion in the forthcoming Gazette 6. Thepicture below shows the instrument in yetanother incarnation as supplied by the“ArtRoom” at £29.95. Whereas earlierversions had the code letters interpreted on theback, this desk model has a ‘window’ with arevolving display.
Science Museum LibraryYou may be aware through articles in
the press that proposals have been made toremove this valuable reference source from theScience Museum in London and split it up,distributing the parts to various otherinstitutions. This being proposed on thegrounds of economy and probably “for yourconvenience”!
At the present time the library hasbeen given a reprieve whilst an external reviewis carried out into the funding of the NationalMuseum of Science and Industry of which theScience Museum Library is a part. The break-up of the library is therefore on hold for a year.
The very suggestion that the libraryshould be split up must fill most of us withdismay. Whilst we may not avail ourselves ofthe services of the library on a regular basis,we are very aware of its usefulness and thehelpful assistance we receive from the staff onthose occasions when information is requested.The UKSRC therefore plans to writeexpressing our dismay at any plans for a break-up of the library and we invite individualmembers to also write lobbying for theretention of the status quo.
If you would like to put pen to paperplease contact:
Jon TuckerHead of the Science Museum
Science MuseumExhibition Road
London SW7 2DD
[Ed’s note: The above comments have beenmade known to the Science Museum with thefollowing additional observation from BruceWilliams: We are particularly worried about the unique,irreplaceable, extensive, but largelyuncatalogued, collection of Corporatearchives. One of our members, BruceWilliams, has by his own efforts been helpingIan Carter to create an Excel data base listingmany items, but alas only a small proportionof the whole.]
Insurance
Connoisseur Collectors Policies nowcover Private Collections at home andanywhere else in the United Kingdom. Foreach £5,000 unit of cover purchase, up to£1,000 applies to items away from home, to amaximum limit of £10,000. Postal “sendings”within the UK are covered up to £250 each.
Because these policies are availableon line, cover can be purchased immediately,so the new “find” that you have just purchasedcan be insured for the journey home.
Existing clients can take up to 20% oftheir collections (by value) to fairs andexhibitions or have them insured atauctioneers’ premises whilst they are beingsold. Items will also be covered whilst they areat valuers or repairers.
Of course there are limitations. Theftfrom unattended vehicles are excluded andthefts from buildings have to show signs of abreak in, but by and large the cover is as wideas one can expect to find from this type ofpolicy. Professional valuations are required foritems that need to be insured for over £1,000and “Collectibles” that are worth over £500have to be insured under a specific headingsuch as “Clocks, Watches and Barometers”.
You can apply for cover by telephoneusing the helpline on 0870 241 0 142, get helpin completing an online application or havequotations made.
The online policy is available forcollections worth up to £50,000. Larger sumsinsured will be quoted individually.
www.connoisseurpolicies.com 01306 734600
IM 2005 update13
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Skid Stick Issue 20June 2005
The programme and arrangements forIM 2005 are proceeding smoothly thanks to thediligent(?) work of the committee. Since thepreparation of the first provisional programme,two further items have been added. DavidRance will be presenting his findings onMusical Slide Rules and we plan to have asmall display of OH Projection SRs. Tocompliment the OHP SRs – does anyone havea 35mm projection demonstration/teachingslide rule? If you do, please contact PeterHopp. Likewise, anyone with information onmusical slide rules is asked to contact DavidRance.
Further information to add to theAston & Mander database will be welcomedby Ray Hems and biographical information anddetails of books by Charles Hoare will beappreciated by Tom Martin who adds “I amgrateful for the responses to the request in thelast Skid Stick for information on the differentissues of Hoare’s “The Slide Rule and how touse it”. Unfortunately I have not been able tofind anything earlier than the 8th impression(1901). I know that the book was first issuedin 1867/8. Information on any issue iswelcome but I would particularly welcomenews of early material. The last impressionsof Hoare’s book advertise “The Slide RuleSimplified together with a 10" Dietzgen sliderule” by C H Harris, BS, MS, Sc D, (anAmerican author), published by The TechnicalPress Ltd., London. This is likely to be C OHarris, whose book of the same title seems tobe readily available through American second-hand book sellers. Does anyone have copiesor information on the Technical Presspublication, with or without a slide rule?”
Rod Lovett has been co-opted/persuaded on to the IM 2005 organisingcommittee and has “volunteered” to try to keepour website up to date with the latest news.Already you will notice an improvement on thesite – www.sliderules.org.uk - click on IM2005 or go straight to:-
www.sliderules.org.uk/im2005/im2005.htmFinally, can we please ask that those
hoping to attend the meeting do so at theearliest opportunity. Even if you are not ableto commit yourself fully at this time as it willassist greatly in the overall organisation.Please let Tom Martin know.
For details of accommodation outsidethe hotel venue, delegates will find thefollowing address helpful:
www.visitcambridge.orgPlease feel free to contact any
member of the committee for any further
information you require. We will look forwardto seeing you.Contacts - Committee
Peter [email protected]
Colin [email protected]
Aston & ManderRay Hems
David [email protected]
Charles HoareTom Martin
[email protected] and 35mm slides
Peter [email protected]
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