• Magnifying glass on the backside of a simplex slide rule pre 1900
    Publicado el Martes, 24 de Mayo de 2022 a las 19:47 CEST por Andreas.Fassbender@... (Andreas Faßbender)
    Hello all,does anyone know a manufacturer who used a semicircular glass cylinder, on the back as a magnifying glass before 1900?Kind regards,Andreas

  • Re: Use of Inverse LogLog scales First resume
    Publicado el Viernes, 20 de Mayo de 2022 a las 16:21 CEST por andreas.poschinger@... (Andreas Poschinger)
    Hi,I interpret Rods questions also like do we really need inverse LL scales?From my point of view not necessarily. In most practical cases I knowabout the use of LL scales ...

  • Re: Use of Inverse LogLog scales Part 5: Logarithms
    Publicado el Viernes, 20 de Mayo de 2022 a las 15:02 CEST por andreas.poschinger@... (Andreas Poschinger)
    Hi,this part is now about the use for logarithms for numbers smaller than1, that I've almost forgot.I still teach Bode (though in my practical time never applied) with theamplidude response ...

  • Re: Use of Inverse LogLog scales Part 4: Hyperbolic functions
    Publicado el Jueves, 19 de Mayo de 2022 a las 17:04 CEST por andreas.poschinger@... (Andreas Poschinger)
    Hi,indeed I lost at least one use case: logarithms of numbers smaller than1. This I will put into part 5. Any other use cases lost?Hyperbolic functions are of some importance ...

  • Re: Use of Inverse LogLog scales Part 3: Expressions containing e^(-t/T)
    Publicado el Jueves, 19 de Mayo de 2022 a las 15:25 CEST por andreas.poschinger@... (Andreas Poschinger)
    Hi,the third application is the computation of expressions containinge^(-t/T), especially the calculation of tables of values for thesefunctions. For this application the inverse loglog scales are notnecessarily needed, but make ...

  • Re: Use of Inverse LogLog scales Part 2: Arbitrary powers of numbers small than one
    Publicado el Jueves, 19 de Mayo de 2022 a las 09:56 CEST por andreas.poschinger@... (Andreas Poschinger)
    Hi,I've forgot to mention arbitrary powers of numbers smaller than onewhich is maybe the most obvious use in most instructions.Let's look on 15*(0.5^3).If we only have LL1-LL3 then we need ...

  • Re: Use of Inverse LogLog scales Part 1: Absolute inverse numbers
    Publicado el Miércoles, 18 de Mayo de 2022 a las 22:11 CEST por andreas.poschinger@... (Andreas Poschinger)
    PS: Ive meant I hope that I do not bore you.... ... allready late;technically it is hopefully ok!-) Good night!Am 18.05.2022 um 22:09 schrieb Andreas Poschinger:

  • Use of Inverse LogLog scales Part 1: Absolute inverse numbers
    Publicado el Miércoles, 18 de Mayo de 2022 a las 22:09 CEST por andreas.poschinger@... (Andreas Poschinger)
    Hi,I hope that I not borrow, since by sure all can be also read in manuals.The most simpliest use of inverse LogLog scales together with nomalLogLog scales are absolute inverse ...

  • Re: lologs and ilologs
    Publicado el Miércoles, 18 de Mayo de 2022 a las 20:53 CEST por andreas.poschinger@... (Andreas Poschinger)
    Hi Rod,today I have an online meeting. I will write something together the nextdays. The mean usages for me right now are:Inverse numbers in their precise value without taking care ...

  • Re: lologs and ilologs
    Publicado el Miércoles, 18 de Mayo de 2022 a las 20:36 CEST por rod@... (Rod Lovett)
    Hi Andreas,I was merely interested in the uses for an inverse log log function.Regards,Rod

  • Re: lologs and ilologs
    Publicado el Miércoles, 18 de Mayo de 2022 a las 12:27 CEST por andreas.poschinger@... (Andreas Poschinger)
    Hi Rod,to be honest, when flying over the paper I did not find the point in thepaper other that somehow the invention history of the inverse Loglogscales is described. Did ...

  • Re: lologs and ilologs
    Publicado el Miércoles, 18 de Mayo de 2022 a las 10:36 CEST por rod@... (Rod Lovett)
    Hi Andreas,I think that you are correct.I hadn't associated the "i" with inverse.Now I would like to see some useful applications of these ideas!Best wishes,Rod

  • Re: lologs and ilologs
    Publicado el Martes, 17 de Mayo de 2022 a las 22:34 CEST por andreas.poschinger@... (Andreas Poschinger)
    PS: I found in your literature search an article:Author    Bob OtnesTitle    Log Log Scales - RevisitedLocation    Journal of the Oughtred Society Vol. 4, No. 1, March, 1995 Pg 9This fits ...

  • Re: lologs and ilologs
    Publicado el Martes, 17 de Mayo de 2022 a las 21:59 CEST por andreas.poschinger@... (Andreas Poschinger)
    Hi Rod,I did not look into the old messages (due to time restriction...); thismay however senseful to solve the puzzle in order to know what Bob hastriggert to write this.May ...

  • lologs and ilologs
    Publicado el Martes, 17 de Mayo de 2022 a las 14:30 CEST por rod@... (Rod Lovett)
    Hello Everyone,Back in 2006 ( ISRG #29477 ) Bob Otnes (sadly no longer with us) wrote the following:Seeing the current interest in logs and cologs, it might be that somereaders ...

  • Re: Do any duplex circular slide rules have the front and back center disc connected?
    Publicado el Martes, 17 de Mayo de 2022 a las 06:46 CEST por markad7ef@... (Mark Davis)
    I must add that, while the discs are connected front to back, there doesn't appear to be any useful way to chain calculations from front to back. In any case, ...

  • Re: Do any duplex circular slide rules have the front and back center disc connected?
    Publicado el Martes, 17 de Mayo de 2022 a las 06:38 CEST por markad7ef@... (Mark Davis)
    The Dempster RotaRule model 'A' and model 'AA'  circular slide rules have a single central disk that is functional on both the front and back of the rule. These slide ...

  • Do any duplex circular slide rules have the front and back center disc connected?
    Publicado el Martes, 17 de Mayo de 2022 a las 01:48 CEST por dpressnall@...
    I just got in a Concise 300 as my first duplex circular slide rule.  The front and back center discs on this one move independently.  I was wondering if there ...

  • Re: Added Folder /S.I.C. 1610 Manual
    Publicado el Domingo, 08 de Mayo de 2022 a las 19:40 CEST por eamonn123@... (Eamonn)
    Hi Steve,Thank you for taking the time to scan and upload the S.I.C. 1610 manual. I really appreciate it.Best regards,Eamonn.

  • Added Folder /S.I.C. 1610 Manual
    Publicado el Domingo, 08 de Mayo de 2022 a las 18:23 CEST por @...
    StephenK <thekays100@...> added folder /S.I.C. 1610 Manual