Brad -
I will defer to Wolfgang, but my translation of
Bei stundenwinkel und deklination zwischen 0 und 0 20 sowie bei
stundenwinkel 90 ist der Hohenrechenschieber nicht zu verwenden
is:
For hour-angle and declination between 0 and 0 20' as well as for hour-angle of 90, the altitude slide is not to be used.
The two dots above the o are called an umlaut (Höhenrechenscheiber). The ö sound is made by shaping your lips as though you were going to say 'oh', then trying to say 'ee'.
Hewitt
Sent from my iPad
On Jan 27, 2013, at 4:11 PM, "Brad Morris" wrote:
> Hi Gary
>
> On the inner tube of my MHR1 (noted as tube II in the German instructions &
> also the scale upon which we set the declination), the minimum angular
> dimension is 20 min (179 deg 40 min). At the other end of this same scale
> I find 89 deg 40 min (90 deg 20 min).
>
> Tube I (outer tube, upon which in the first step we set zero, or in the
> third step, upon which we set azimuth) starts at zero. The other end of
> tube I is marked 89 deg 40 min (90 deg 20 min). The double markings begin
> at 35 deg (145 deg). Below 35 deg, there is only a single mark, obviously
> just due to limited room.
>
> I thought to mention this as your email indicates that the smallest angular
> dimension on this scale is 30 min. Not true for mine. I simply don't know
> about others.
>
> There ARE special instructions (in German) for when "stundenwinkel" (t)
> and "deklination" are between 0 and 0 deg 20 min. I cannot read German. I
> include the text following. All typo's are mine.
>
> Bei stundenwinkel und deklination zwischen 0 und 0 20 sowie bei
> stundenwinkel 90 ist der Hohenrechenschieber nicht zu verwenden.
>
> The first 'o' in Hohenrechenschieber has the two dots above it.
>
> Regards
> Brad
> On Jan 27, 2013 6:39 PM, "Gary LaPook" wrote:
>
>> ------------------------------
>> Do you have any actual instructions for using your MHR-1 for dealing with
>> the special case when the declination is less than the lowest declination
>> marked on the tangent (or co-tangent) scale, 20' for the Bygrave and 30'
>> for the MHR-1 and 50' on my flat Bygrave? I have never been able to find
>> instructions for this situation. I am attaching a description for the use
>> of this instrument (in French) which says it is "inutilisable" for this
>> situation and the original Bygrave instruction manual is silent as to this
>> situation, also attached.
>>
>> I came up with a method of dealing with this situation and it is posted on
>> my website at:
>>
>> https://sites.google.com/site/fredienoonan/other-flight-navigation-information/modern-bygrave-slide-rule
>>
>> (In my notation "W" is the same as "y" in Bygrave's notation and "x" on
>> the MHR-1.)
>>
>> "When declination is less than one degree you can't begin the computation
>> the normal way to find "W" because you have to start the process with
>> declination on the cotangent scale and this scale doesn't extend below 1º.
>> So in this case you just skip the computation of "W" and simply set "W"
>> equal to declination. Using this method you arrive at an azimuth that is
>> not exact but is a close approximation and in the worst case I have found
>> the azimuth is still within 0.9º of the true azimuth but most are much
>> closer. If the declination is less than one degree and the latitude is also
>> less than one degree, follow this procedure and also assume a latitude
>> equal to one degree. After you have computed the Az you then follow the
>> same procedure discussed above for azimuths exceeding 85º by interchanging
>> the latitude and declination and then computing Hc which will produce an
>> exact value of Hc."
>>
>> Also see my prior post at:
>>
>>
>>
>> http://fer3.com/arc/m2.aspx/Computing-azimuth-with-Bygrave-special-cases-LaPook-feb-2010-g11826
>>
>> gl
>>
>>
>> --- On *Sun, 1/20/13, Marc Giordan * wrote:
>>
>>
>> From: Marc Giordan
>> Subject: [NavList 22013] Re: Dennert & Pape MHR-1 Dennert & Pape MHR-1
>> HR-2 Cylindrical Slide LineRuler
>> To: garylapook---net
>> Date: Sunday, January 20, 2013, 11:08 AM
>>
>> ------------------------------
>>
>> Sir,
>> I am French and also quite familiar with the use of the MHR 1 at sea (I
>> used it for 2 atlantic crossings by sail)
>> Would any one wish to be trained in using it, I am ready to help !
>> The MHR 1 was bought by my father some 30 years ago at the flee market in
>> Paris
>> Yours
>> Marc Giordan
>> 26 rue de Paris
>> 78560 le Port Marly
>> (0033)675210703
>> ----------------------------------------------------------------
>> NavList message boards and member settings: www.fer3.com/NavList
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>>
>> : http://fer3.com/arc/m2.aspx?i=122013
>>
>> *Attached File: 122138.calcul de navigation, v2 (courante).pdf
>> *
>> *Attached File: 122138.bygrave manual.pdf
>> *
>>
>> : http://fer3.com/arc/m2.aspx?i=122138
>>
>
>
>
>
> : http://fer3.com/arc/m2.aspx?i=122139
>
>
: http://fer3.com/arc/m2.aspx?i=122143
