> Usually cursorless rules are only described as 'very good' condition!

Well, that would require that the seller realise that the rule is actually
missing a part.  Having had it pointed out to her, she's promptly updated
the listing.

So, it's not a point for criticism - it's a point for praise of a good
eBayer.

Regards, Dave S

----- Original Message -----
From: "Jones, Jon C." <jcjones@...>
To: <sliderule@yahoogroups.com>
Sent: Tuesday, November 24, 2009 1:43 AM
Subject: SR minty rules and true antiques


> Item 370295320775.  A MINT rule that is missing its cursor.  Usually
> cursorless rules are only described as 'very good' condition!
>
>
>
> 260511411703, 260511412786.  How 'bout these guys?  Now I daresay these
> can be called rare, vintage, or even antique.
>
>
>
> [Non-text portions of this message have been removed]
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>


--------------------------------------------------------------------------------



No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 8.5.425 / Virus Database: 270.14.77/2520 - Release Date: 11/22/09
19:40:00

Hi Marion,

No flame taken!

Try this URL, very similar to the previous but a much bigger picture.

http://sliderules.lovett.com/aristodarmstadt967umagnifier/aristodarmstadt967umag\
nifierpics.htm

or

http://tinyurl.com/y95dbqr


Regards,

Rod




--- In sliderule@yahoogroups.com, "sliderulenut" <jayhawk999@...> wrote:
>
> Thanks, Rod, John and Jerry, for your comments. I didn't suggest a flame but
after another look, my screen is quite blurred on the left and I still can't
make a clear reading on the 'z' but this is my problem. I accept your
interpretations.
>
> It is curious how makers seem to find ways to make variants on their rules. I
have a couple of rules, I can't find them now, that don't have any labels on the
left and only self-documents labels on the right. These have 'x' for both C and
D scales. These would be hard fora  beginner to deal with. I have become so
familiar with most rules that my eye goes directly to the scale of interest.
Only rarely do i have to look. This most often is on rules with very close scale
spacing, so I look at labels to be sure.
>
> It is interesting on Flying Fish rules, I have a 1002 and 1002, which use
roman letters as scale labels and not Chinese. It would be interesting to learn
why. The right-hand labels are scale numeric ranges but no self-documenting
labels.
>
> Marion
>
> --- In sliderule@yahoogroups.com, "rodlovett" <rod@> wrote:
> >
> > Hi Marion,
> >
> > Quite right!  They are zeds (zees)  z's.
> >
> > It's quite unusual for Aristo to confuse the users.  I wonder why they used
that notation.
> >
> > The rule came to me with to cursors (one a magnifier). I'm sure it wasn't
sold that way.
> >
> > Regards,
> >
> > Rod
> >
> > --- In sliderule@yahoogroups.com, "sliderulenut" <jayhawk999@> wrote:
> > >
> > > I saw it on Rod's site. Here is the url
> > >
http://sliderules.lovett.com/aristodarmstadt967umagnifier/aristodarmstadt967umag\
nifier.htm
> > > and it show two cursors -- one of them a magnifier.
> > >
> > > The twos (z) showed up with sharp corners to me on Rod's site -- and my
eye sight is quite good so my opthamologist says --for an old guy.
> > >
> > > Marion
> >
>

My criticism is in the confidence that we can place on buyer's descriptions. 
Even the relatively good pictures supplied by this seller are not sufficient to
verify the condition.  So you are basically getting a pig in a polk.  This is
just the hazards of ebay, I guess.

Nonetheless, when somebody who is selling something makes an appraisal,
especially one so high as 'mint', I expect them to know what that means.  It
does not mean, in my opinion "I don't know what this is, or what it does, or how
to use it, but it doesn't appear damaged or broken."

However, this doesn't get me indignant.  What does get me a bit indignant is
when someone KNOWS it is missing a cursor or other piece, but has the chutzpah
to say that it is 'easy to replace'.  One seller has done this on multiple
occassions.  I wrote them and asked them about their source for cursor parts,
telling them there is quite a market and we could make some money.  They never
wrote back.




________________________________

From: sliderule@yahoogroups.com on behalf of David Smart
Sent: Mon 11/23/2009 4:15 PM
To: sliderule@yahoogroups.com
Subject: Re: SR minty rules and true antiques




> Usually cursorless rules are only described as 'very good' condition!

Well, that would require that the seller realise that the rule is actually
missing a part. Having had it pointed out to her, she's promptly updated
the listing.

So, it's not a point for criticism - it's a point for praise of a good
eBayer.

Regards, Dave S

----- Original Message -----
From: "Jones, Jon C." <jcjones@...
<mailto:jcjones%40geodecisions.com> >
To: <sliderule@yahoogroups.com <mailto:sliderule%40yahoogroups.com> >
Sent: Tuesday, November 24, 2009 1:43 AM
Subject: SR minty rules and true antiques

> Item 370295320775. A MINT rule that is missing its cursor. Usually
> cursorless rules are only described as 'very good' condition!
>
>
>
> 260511411703, 260511412786. How 'bout these guys? Now I daresay these
> can be called rare, vintage, or even antique.
>
>
>
> [Non-text portions of this message have been removed]
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>

----------------------------------------------------------

No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 8.5.425 / Virus Database: 270.14.77/2520 - Release Date: 11/22/09
19:40:00






[Non-text portions of this message have been removed]

I once bought via eBay a set of Portuguese mint coins. They were made by the
Portuguese mint but not in mint condition. I got a refund.

Ronald

> -----Original Message-----
> From: sliderule@yahoogroups.com [mailto:sliderule@yahoogroups.com] On
> Behalf Of Jones, Jon C.
>
> Nonetheless, when somebody who is selling something makes an appraisal,
> especially one so high as 'mint', I expect them to know what that
> means.  It does not mean, in my opinion "I don't know what this is, or
> what it does, or how to use it, but it doesn't appear damaged or
> broken."
>

My Fowler calculator has an annoying fault. The front cursor (and hence the back
dial) sometimes get dragged round when I am setting the front dial. This only
happens when the cursor is in a particular location, about 20 degrees of the
whole circumference, and is independent of the dial setting. I can see no
distortion of the dials nor cursor and so suspect the fault lies with the drive
mechanism. This I presume involves crown wheels and pinions with concentric
shafts to dials and cursor. I should like to rectify this, which means
separating the case.
Has anyone any experience of splitting the case, which appears to be a press
fit?

Peter Johnson

As an old back-woods Southerner, I have to make a minor correction to Jon
Jones' analogy. The correct term is "...buying a pig in a poke..", not
"...pig  in a polk...".  A "poke" is a sack or bag.
(:>)

Cyron Lawson


[Non-text portions of this message have been removed]

260512028399



As per my ‘lots’ rant the other day.   13 brand new Concise keychain slide
rules.  The only reason I can think of for somebody to buy this is so they can
sell them individually.  So they will be looking for a ‘wholesale’ price.  I
guess the seller think that the box has some value, but I think they are wrong.



Slide rule search says they are worth about 20 bucks each, so these should bring
in 260 dollars easily if sold separately.  I put a bid in so I will watch and
see what they go for.



[Non-text portions of this message have been removed]

The artillery slide rules produced for the British Army by A G Thornton and by
Blundell Harling had two cursors as standard. Two examples of these can be seen
on my website: www.mathsinstruments.me.uk on the relevant maker's pages.

Other A G Thornton slide rules are also sometimes found with two cursors where
the original owner added the optional three line cursor to the standard one line
one.

David M Riches

--- In sliderule@yahoogroups.com, CTLPELWV@... wrote:
>
> The only rule intended to operate with 2-cursors that  I've  encountered
> (verbally, not in person) is the Hemmi 154 rule for electrical  engineering.
> (I think I'm remembering the maker/model correctly). My  half-brother's step
> father (how's that for a convoluted family?) used one on his  job in a power
> plant. My half-brother was duly impressed, to the point that he  eventually
> enrolled in engineering school, only to discover that he was better  fitted
> to be a technical writer.
>
> Post sold a multi-cursor rule (4 or 6?) for specialized control system
> response calculations.  Don't recall the model.
>
> In my father's used furniture, etc. shop, I recall seeing a sliderule with
> two cursors, but that was only to give the buyer an option-- one flat
> glass, one  with the half-round"magnifier". I recall it was plain,
white-painted
> wood in a  flimsy blue cardboard box-- obviously a Lawrence.
>
> Cyron Lawson
>
>
> [Non-text portions of this message have been removed]
>

Thanks, Rod, that photo is quite clear and without blurs to me. Those are
definitely 'zeds' and not twos. This is nice looking rule.

Marion

--- In sliderule@yahoogroups.com, "rodlovett" <rod@...> wrote:
>
> Hi Marion,
>
> No flame taken!
>
> Try this URL, very similar to the previous but a much bigger picture.
>
>
http://sliderules.lovett.com/aristodarmstadt967umagnifier/aristodarmstadt967umag\
nifierpics.htm
>
> or
>
> http://tinyurl.com/y95dbqr
>
>
> Regards,
>
> Rod
>
>
>
>
> --- In sliderule@yahoogroups.com, "sliderulenut" <jayhawk999@> wrote:
> >
> > Thanks, Rod, John and Jerry, for your comments. I didn't suggest a flame but
after another look, my screen is quite blurred on the left and I still can't
make a clear reading on the 'z' but this is my problem. I accept your
interpretations.
> >
> > It is curious how makers seem to find ways to make variants on their rules.
I have a couple of rules, I can't find them now, that don't have any labels on
the left and only self-documents labels on the right. These have 'x' for both C
and D scales. These would be hard fora  beginner to deal with. I have become so
familiar with most rules that my eye goes directly to the scale of interest.
Only rarely do i have to look. This most often is on rules with very close scale
spacing, so I look at labels to be sure.
> >
> > It is interesting on Flying Fish rules, I have a 1002 and 1002, which use
roman letters as scale labels and not Chinese. It would be interesting to learn
why. The right-hand labels are scale numeric ranges but no self-documenting
labels.
> >
> > Marion
> >
> > --- In sliderule@yahoogroups.com, "rodlovett" <rod@> wrote:
> > >
> > > Hi Marion,
> > >
> > > Quite right!  They are zeds (zees)  z's.
> > >
> > > It's quite unusual for Aristo to confuse the users.  I wonder why they
used that notation.
> > >
> > > The rule came to me with to cursors (one a magnifier). I'm sure it wasn't
sold that way.
> > >
> > > Regards,
> > >
> > > Rod
> > >
> > > --- In sliderule@yahoogroups.com, "sliderulenut" <jayhawk999@> wrote:
> > > >
> > > > I saw it on Rod's site. Here is the url
> > > >
http://sliderules.lovett.com/aristodarmstadt967umagnifier/aristodarmstadt967umag\
nifier.htm
> > > > and it show two cursors -- one of them a magnifier.
> > > >
> > > > The twos (z) showed up with sharp corners to me on Rod's site -- and my
eye sight is quite good so my opthamologist says --for an old guy.
> > > >
> > > > Marion
> > >
> >
>

Just for info's sake, perpetual calendars are never 'out of date'. The
one supported by the Concise #32 "starts in 1960 and ends with 1981".

http://www.timeanddate.com/calendar/repeating.html?country=1&year=1960
is a link to a site, Time and Date, which builds a table for any given
year of other year's calendars which work for that year and vs. versa.
It says that the 1960 calendar works for:
1864  96 years before
1892  68 years before  + 28 years
1904  56 years before  + 12 years
1932  28 years before  + 28 years
1960  current year        + 28 years
1988  28 years after     + 28 years
2016  56 years after     + 28 years
2044  84 years after     + 28 years
2072  112 years afte   r+ 28 years
 with the caveat that holidays may be different!

So not only are these in-the-bag NOS, but they are still usable, with
a little attention.

Incidentally, one reason I knew about this was the short-int overflow
in the date used for Vax/VMS. When I was at the UT Research center, I
shepherded a microVAX which provided email for technicians. (Engineers
and scientists got email automatically through the computer center: I
got the cast-off old-iron microvax II because no one else wanted it,
The license still had a few years on it. I had previously scavenged a
pair of Sun workstations which I handed off to the email guy to make
servers out of, and thus won a connection through the email network.
All I had to do was make user accounts for each technician who evinced
interest!)

Anyway, one day I came in and my microVAX was lying on its face in the
dirt (virtually), because its license had expired. The short-int
overflow had set it back to some year in the early 1900's, and the
license program read that as the current date, well outside of the
couple-of-years that it considered my license to be in effect. It was
a precursor to the Y2K problem that was due to come in less than two
decades!

I hopped on a unix machine (where I was administering the TeX
installation) and got on the VAX mailing list, and watched the emails
come in, all through unix mailing systems, as VAX machines 9 hours
behind me crossed the midnight point and shut down, and the users
(just behind me) discovered it... and then watched as the reports of
failures continued with the work-starting-hour around the globe.

Within a few hours, someone found and reported a year that we could
set the clock to. I don't even remember which year it was, but it had
the same day-of-the-week lineup with the year that was, then, current,
and happened after the VAX license utility was first written, thus
qualifying our machines as still properly licensed.

This news also gave the hint about how to successfully keep VMS going
after the license has run out, but I never got to be a criminal that
way, because I was laid off in the Great Technician Reassignment
Debacle which came the year after.

ray

On Tue, Nov 24, 2009 at 9:54 AM, Jones, Jon C. <jcjones@...> wrote:
>
>
>
>
>
> 260512028399
>
>
>
> As per my ‘lots’ rant the other day. 13 brand new Concise keychain slide
rules. The only reason I can think of for somebody to buy this is so they can
sell them individually. So they will be looking for a ‘wholesale’ price. I guess
the seller think that the box has some value, but I think they are wrong.
>
>
>
> Slide rule search says they are worth about 20 bucks each, so these should
bring in 260 dollars easily if sold separately. I put a bid in so I will watch
and see what they go for.
>
>
> [Non-text portions of this message have been removed]
>
>

President James K. Polk wasn't Jewish or Muslim was he?

After a hearty breakfast, you could indeed have some pig in the Polk.

But I digress (jus' Polking around) ...           8^)

CTLPELWV@... wrote:
> As an old back-woods Southerner, I have to make a minor correction to Jon
> Jones' analogy. The correct term is "...buying a pig in a poke..", not
> "...pig in a polk...". A "poke" is a sack or bag.
> (:>)
>
> Cyron Lawson
--
take care,
	 -- Vince
Speed of light is 1 799 884 800 000 furlongs per fortnight.

--- In sliderule@yahoogroups.com, "Jones, Jon C." <jcjones@...> wrote:
>
>
>
>
>
> 260512028399
>
>
>
> As per my ‘lots’ rant the other day.   13 brand new Concise keychain slide
rules.  The only reason I can think of for somebody to buy this is so they can
sell them individually.  So they will be looking for a ‘wholesale’ price.  I
guess the seller think that the box has some value, but I think they are wrong.

A baker's dozen, according to the box end. Buy twelve, get one free?

Peter Johnson

Has anybody ever established why artillery rules needed two cursors? I have
never seen a convincing explanation. My own theory was that there are two
solutions for ballistics equations - one that lobs the shell up high to land
on the target, the other that uses a flat trajectory.

But surely somebody must know the definitive answer.

Chris Bourne
London UK

On Tue, Nov 24, 2009 at 5:16 PM, weymouthdavid <drdriches@...> wrote:

>
>
> The artillery slide rules produced for the British Army by A G Thornton and
> by Blundell Harling had two cursors as standard. Two examples of these can
> be seen on my website: www.mathsinstruments.me.uk on the relevant maker's
> pages.
>
> Other A G Thornton slide rules are also sometimes found with two cursors
> where the original owner added the optional three line cursor to the
> standard one line one.
>
> David M Riches
>
> --- In sliderule@yahoogroups.com <sliderule%40yahoogroups.com>, CTLPELWV@...
> wrote:
> >
> > The only rule intended to operate with 2-cursors that I've encountered
> > (verbally, not in person) is the Hemmi 154 rule for electrical
> engineering.
> > (I think I'm remembering the maker/model correctly). My half-brother's
> step
> > father (how's that for a convoluted family?) used one on his job in a
> power
> > plant. My half-brother was duly impressed, to the point that he
> eventually
> > enrolled in engineering school, only to discover that he was better
> fitted
> > to be a technical writer.
> >
> > Post sold a multi-cursor rule (4 or 6?) for specialized control system
> > response calculations. Don't recall the model.
> >
> > In my father's used furniture, etc. shop, I recall seeing a sliderule
> with
> > two cursors, but that was only to give the buyer an option-- one flat
> > glass, one with the half-round"magnifier". I recall it was plain,
> white-painted
> > wood in a flimsy blue cardboard box-- obviously a Lawrence.
> >
> > Cyron Lawson
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>
>


[Non-text portions of this message have been removed]

Yeah, it looked wrong, but I was in haste.  And for some reason I always get it
momentarily confused with silk purse/sow's ear.   My agrarian metaphors
obviously need polish.



Sent from my Verizon Wireless BlackBerry

-----Original Message-----
From: CTLPELWV@...
Date: Tue, 24 Nov 2009 15:01:25
To: <sliderule@yahoogroups.com>
Subject: SR OT- Minor dialect correction

As an old back-woods Southerner, I have to make a minor correction to Jon
Jones' analogy. The correct term is "...buying a pig in a poke..", not
"...pig  in a polk...".  A "poke" is a sack or bag.
(:>)

Cyron Lawson


[Non-text portions of this message have been removed]




[Non-text portions of this message have been removed]

It's called indirect fire and direct fire.

Connected by MOTOBLURâ„¢ on T-Mobile

-----Original message-----
From: Chris <cfpb@...>
To: sliderule@yahoogroups.com
Sent: Wed, Nov 25, 2009 04:59:14 GMT+00:00
Subject: Re: SR Re: Re- Two cursors on one rule

Has anybody ever established why artillery rules needed two cursors? I have
never seen a convincing explanation. My own theory was that there are two
solutions for ballistics equations - one that lobs the shell up high to land
on the target, the other that uses a flat trajectory.

But surely somebody must know the definitive answer.

Chris Bourne
London UK

On Tue, Nov 24, 2009 at 5:16 PM, weymouthdavid <drdriches@...> wrote:

>
>
> The artillery slide rules produced for the British Army by A G Thornton and
> by Blundell Harling had two cursors as standard. Two examples of these can
> be seen on my website: www.mathsinstruments.me.uk on the relevant maker's
> pages.
>
> Other A G Thornton slide rules are also sometimes found with two cursors
> where the original owner added the optional three line cursor to the
> standard one line one.
>
> David M Riches
>
> --- In sliderule@yahoogroups.com <sliderule%40yahoogroups.com>, CTLPELWV@...
> wrote:
> >
> > The only rule intended to operate with 2-cursors that I've encountered
> > (verbally, not in person) is the Hemmi 154 rule for electrical
> engineering.
> > (I think I'm remembering the maker/model correctly). My half-brother's
> step
> > father (how's that for a convoluted family?) used one on his job in a
> power
> > plant. My half-brother was duly impressed, to the point that he
> eventually
> > enrolled in engineering school, only to discover that he was better
> fitted
> > to be a technical writer.
> >
>


[Non-text portions of this message have been removed]

I happen to have another British slide rule with two identical cursors, a
Reliance. A fairly simple one with A/B C/D and S L T on the back of the
slide. Nicely made, celluloid on mahogany. Pretty good condition, only a
little tight. The conversions and constants on the back side are very clear,
engraved on celluloid rather than printed on paper.

Now, this one I don't need and I will give it away to somebody who will give
it a good home :-)
Just send me your address, if there is more than one applicant, I will draw
for the winner...

Good luck!

John Mosand

>The artillery slide rules produced for the British Army by A G Thornton and
by Blundell Harling had two cursors as standard. Two examples of these can
be seen on my website: www.mathsinstruments.me.uk on the relevant maker's
pages.

Other A G Thornton slide rules are also sometimes found with two cursors
where the original owner added the optional three line cursor to the
standard one line one.

David M Riches

--- In sliderule@yahoogroups.com, CTLPELWV@... wrote:
>
> The only rule intended to operate with 2-cursors that  I've  encountered
> (verbally, not in person) is the Hemmi 154 rule for electrical
engineering.
> (I think I'm remembering the maker/model correctly). My  half-brother's
step
> father (how's that for a convoluted family?) used one on his  job in a
power
> plant. My half-brother was duly impressed, to the point that he
eventually
> enrolled in engineering school, only to discover that he was better
fitted
> to be a technical writer.
>
> Post sold a multi-cursor rule (4 or 6?) for specialized control system
> response calculations.  Don't recall the model.
>
> In my father's used furniture, etc. shop, I recall seeing a sliderule with
> two cursors, but that was only to give the buyer an option-- one flat
> glass, one  with the half-round"magnifier". I recall it was plain,
white-painted
> wood in a  flimsy blue cardboard box-- obviously a Lawrence.
>
> Cyron Lawson
>
>
> [Non-text portions of this message have been removed]
>

There seems to be some confusion here. As a former gunner I can tell you that
the terms high angle & low angle and indirect fire & direct fire are NOT
synonymous.

Direct fire is where the target can be seen from the gun position and the gun is
directly aimed at the target. It is of course low angle.

However indirect fire can be either low angle (the more usual as it is more
accurate and the time of flight is shorter) or high angle where hills or some
other obstruction prevent the use of low angle. Mortars also use a high angle
trajectory. In indirect fire the target is not observed from the gun position
but from a forward observation post. The observation officer there directs the
shoot by first estimating the target position, which he reports to the gun
position where the range and direction are calculated, and then observes the
fire and sends the corrections necessary to bring the shells onto the target.

I should add that I am not sure that any of this is the reason for there being
two cursors on RA slide rules, since I can see no reason for doing both high and
low angle calculations at the same time. Recently there was an instruction
manual for these rules on ebay but unfortunately I did not win it. Maybe someone
in this group did and may know the answer.

David M Riches

--- In sliderule@yahoogroups.com, "James Johnston" <james30154@...> wrote:
>
> It's called indirect fire and direct fire.
>
> Connected by MOTOBLURâ„¢ on T-Mobile
>
> -----Original message-----
> From: Chris <cfpb@...>
> To: sliderule@yahoogroups.com
> Sent: Wed, Nov 25, 2009 04:59:14 GMT+00:00
> Subject: Re: SR Re: Re- Two cursors on one rule
>
> Has anybody ever established why artillery rules needed two cursors? I have
> never seen a convincing explanation. My own theory was that there are two
> solutions for ballistics equations - one that lobs the shell up high to land
> on the target, the other that uses a flat trajectory.
>
> But surely somebody must know the definitive answer.
>
> Chris Bourne
> London UK
>
> On Tue, Nov 24, 2009 at 5:16 PM, weymouthdavid <drdriches@...> wrote:
>
> >
> >
> > The artillery slide rules produced for the British Army by A G Thornton and
> > by Blundell Harling had two cursors as standard. Two examples of these can
> > be seen on my website: www.mathsinstruments.me.uk on the relevant maker's
> > pages.
> >
> > Other A G Thornton slide rules are also sometimes found with two cursors
> > where the original owner added the optional three line cursor to the
> > standard one line one.
> >
> > David M Riches
> >
> > --- In sliderule@yahoogroups.com <sliderule%40yahoogroups.com>, CTLPELWV@
> > wrote:
> > >
> > > The only rule intended to operate with 2-cursors that I've encountered
> > > (verbally, not in person) is the Hemmi 154 rule for electrical
> > engineering.
> > > (I think I'm remembering the maker/model correctly). My half-brother's
> > step
> > > father (how's that for a convoluted family?) used one on his job in a
> > power
> > > plant. My half-brother was duly impressed, to the point that he
> > eventually
> > > enrolled in engineering school, only to discover that he was better
> > fitted
> > > to be a technical writer.
> > >
> >
>
>
> [Non-text portions of this message have been removed]
>

I read your first line, and was about to reply with the rest of your post.

But then, why only two?  This reminds me of the "cockpit clock rule":
one clock might be wrong; two clocks, which one's right?  So, three clocks.

Chris wrote:
>
>
> Has anybody ever established why artillery rules needed two cursors? I have
> never seen a convincing explanation. My own theory was that there are two
> solutions for ballistics equations - one that lobs the shell up high to land
> on the target, the other that uses a flat trajectory.
>
> But surely somebody must know the definitive answer.
>
> Chris Bourne
> London UK

--
take care,
	 -- Vince
Speed of light is 1 799 884 800 000 furlongs per fortnight.

Sounds interesting. Could you give a numerical example?

--- In sliderule@yahoogroups.com, "James Johnston" <james30154@...> wrote:
>
> It's called indirect fire and direct fire.
>
> Connected by MOTOBLURâ„¢ on T-Mobile

The key is that there are always two possible solutions, a high angle and a low
angle solution, for artillery or mortar weapons. Depending on a number of
factors, there may be two angle solutions that may or may not be direct or
indirect fire -- this is a different concept. I don't think that is the reason
for two cursors but .....
Marion

--- In sliderule@yahoogroups.com, "James Johnston" <james30154@...> wrote:
>
> It's called indirect fire and direct fire.
>
> Connected by MOTOBLURâ„¢ on T-Mobile
>
> -----Original message-----
> From: Chris <cfpb@...>
> To: sliderule@yahoogroups.com
> Sent: Wed, Nov 25, 2009 04:59:14 GMT+00:00
> Subject: Re: SR Re: Re- Two cursors on one rule
>
> Has anybody ever established why artillery rules needed two cursors? I have
> never seen a convincing explanation. My own theory was that there are two
> solutions for ballistics equations - one that lobs the shell up high to land
> on the target, the other that uses a flat trajectory.
>
> But surely somebody must know the definitive answer.
>
> Chris Bourne
> London UK
>
> On Tue, Nov 24, 2009 at 5:16 PM, weymouthdavid <drdriches@...> wrote:
>
> >
> >
> > The artillery slide rules produced for the British Army by A G Thornton and
> > by Blundell Harling had two cursors as standard. Two examples of these can
> > be seen on my website: www.mathsinstruments.me.uk on the relevant maker's
> > pages.
> >
> > Other A G Thornton slide rules are also sometimes found with two cursors
> > where the original owner added the optional three line cursor to the
> > standard one line one.
> >
> > David M Riches
> >
> > --- In sliderule@yahoogroups.com <sliderule%40yahoogroups.com>, CTLPELWV@
> > wrote:
> > >
> > > The only rule intended to operate with 2-cursors that I've encountered
> > > (verbally, not in person) is the Hemmi 154 rule for electrical
> > engineering.
> > > (I think I'm remembering the maker/model correctly). My half-brother's
> > step
> > > father (how's that for a convoluted family?) used one on his job in a
> > power
> > > plant. My half-brother was duly impressed, to the point that he
> > eventually
> > > enrolled in engineering school, only to discover that he was better
> > fitted
> > > to be a technical writer.
> > >
> >
>
>
> [Non-text portions of this message have been removed]
>

No, I can't give a numerical example I

Connected by MOTOBLURâ„¢ on T-Mobile

-----Original message-----
From: hansmilton <hansmilton@...>
To: sliderule@yahoogroups.com
Sent: Wed, Nov 25, 2009 21:31:53 GMT+00:00
Subject: SR Re: Re- Two cursors on one rule

Sounds interesting. Could you give a numerical example?

--- In sliderule@yahoogroups.com, "James Johnston" <james30154@...> wrote:
>
> It's called indirect fire and direct fire.
>
> Connected by MOTOBLUR™ on T-Mobile




[Non-text portions of this message have been removed]

Hello all,

Following up on the recent discussions regarding the relative advantages of
rules with scales folded at sqrt(10) vs. at pi, I decided to write up the method
I use on these rules to avoid getting confused while doing chained calculations
and mixing the folded and unfolded scales.  For those who are interested in
setting the decimal point by digit counting, I also explain the method I use to
compute the digit count correction tally while mixing the scale sets.  Please
let me know if you find any errors so that I can correct them.

Best regards, and to those in the USA, Happy Thanksgiving Day!
Steve Treadwell

A big assortment of very useful Pickett spare parts, a lovely Fowler Universal
calculator set, a FC 2/83N, mystery boxes, and more goodies coming every day!
Wahoo!!

Have a look:
http://www.sphere.bc.ca/test/auction.html

drop by and have some fun and do some good at the same time,
all the best,
walter
The Slide Rule Universe
http://www.sphere.bc.ca/test/sruniverse.html

Steve, does yours differ from Clason's or Snodgrass's method?

marion

--- In sliderule@yahoogroups.com, "dfsmth45" <steve.t123@...> wrote:
>
> Hello all,
>
> Following up on the recent discussions regarding the relative advantages of
rules with scales folded at sqrt(10) vs. at pi, I decided to write up the method
I use on these rules to avoid getting confused while doing chained calculations
and mixing the folded and unfolded scales.  For those who are interested in
setting the decimal point by digit counting, I also explain the method I use to
compute the digit count correction tally while mixing the scale sets.  Please
let me know if you find any errors so that I can correct them.
>
> Best regards, and to those in the USA, Happy Thanksgiving Day!
> Steve Treadwell
>

The Reliance was another British military slide rule, although many Reliances I
have seen, including one I have, do not have two cursors. Possibly it depended
on what arm of the military they were issued to as the Reliance was not specific
to the RA. It was merely 'Rule Slide 10in'.

They are unusual in that the celluloid side rulers are usually reinforced with a
metal mesh moulded in.

David M Riches

--- In sliderule@yahoogroups.com, "John Mosand" <jomosand@...> wrote:
>
>
>
>
> I happen to have another British slide rule with two identical cursors, a
> Reliance. A fairly simple one with A/B C/D and S L T on the back of the
> slide. Nicely made, celluloid on mahogany. Pretty good condition, only a
> little tight. The conversions and constants on the back side are very clear,
> engraved on celluloid rather than printed on paper.
>
> Now, this one I don't need and I will give it away to somebody who will give
> it a good home :-)
> Just send me your address, if there is more than one applicant, I will draw
> for the winner...
>
> Good luck!
>
> John Mosand
>
> >The artillery slide rules produced for the British Army by A G Thornton and
> by Blundell Harling had two cursors as standard. Two examples of these can
> be seen on my website: www.mathsinstruments.me.uk on the relevant maker's
> pages.
>
> Other A G Thornton slide rules are also sometimes found with two cursors
> where the original owner added the optional three line cursor to the
> standard one line one.
>
> David M Riches
>
> --- In sliderule@yahoogroups.com, CTLPELWV@ wrote:
> >
> > The only rule intended to operate with 2-cursors that  I've  encountered
> > (verbally, not in person) is the Hemmi 154 rule for electrical
> engineering.
> > (I think I'm remembering the maker/model correctly). My  half-brother's
> step
> > father (how's that for a convoluted family?) used one on his  job in a
> power
> > plant. My half-brother was duly impressed, to the point that he
> eventually
> > enrolled in engineering school, only to discover that he was better
> fitted
> > to be a technical writer.
> >
> > Post sold a multi-cursor rule (4 or 6?) for specialized control system
> > response calculations.  Don't recall the model.
> >
> > In my father's used furniture, etc. shop, I recall seeing a sliderule with
> > two cursors, but that was only to give the buyer an option-- one flat
> > glass, one  with the half-round"magnifier". I recall it was plain,
> white-painted
> > wood in a  flimsy blue cardboard box-- obviously a Lawrence.
> >
> > Cyron Lawson
> >
> >
> > [Non-text portions of this message have been removed]
> >
>

weymouthdavid wrote:
>
>
> The artillery slide rules produced for the British Army by A G
> Thornton and by Blundell Harling had two cursors as standard. Two
> examples of these can be seen on my website:
> www.mathsinstruments.me.uk on the relevant maker's pages.
>

What is interesting about the Thornton artillery rules is that the two
cursors are not of the same type. Your example, the VF1766 has different
sized cursors, whereas my example, a VF0129, has cursors of the same
size, but different materials. One is plain aluminium, the other has a
painted metal frame, wooden spacers, and brass tongues. Perhaps this
served as some sort of memory aid, or perhaps one of the cursors is not
original.

I have another example of an artillery rule which is almost identical to
the Thornton, but it has no identifying marks, apart from a Commonwealth
broad arrow. Its cursors are identical.

Could the explanation for two cursors be simply that one is a spare in
case of breakage?

John, I'd be very interested in this rule, and happy to pay any postage
costs of course.

John Oakhill

John Mosand wrote:
>
>
>
>
> I happen to have another British slide rule with two identical cursors, a
> Reliance. A fairly simple one with A/B C/D and S L T on the back of the
> slide. Nicely made, celluloid on mahogany. Pretty good condition, only a
> little tight. The conversions and constants on the back side are very
> clear,
> engraved on celluloid rather than printed on paper.
>
> Now, this one I don't need and I will give it away to somebody who
> will give
> it a good home :-)
> Just send me your address, if there is more than one applicant, I will
> draw
> for the winner...
>

Hi Marion,

I am not familiar with Clason - is that available on-line?  As for Snodgrass, I
have only skimmed parts of his book, but it looks like my method for mixing
scales is similar to the one he describes at the end of the section on "The
Electrical Rule".  Well, of course, I suppose it would have to be similar.  He
seems to use "bottom" and "top" rather than "across" and "same" and only refers
to a single inverted R scale rather than both a CI and CIF scale.  The only
place I saw where he talks about digit counting, he seems to just be using C and
D, not folded scales and tallies based on whether or not the slide sticks out to
the right or left - this works OK for C and D, but not for CI or the folded
scales.  As I say, I have only skimmed it, so I could have missed something.  I
would really need to study his book more before I could say just how similar my
method is.  I have a busy day tomorrow, so it will be Friday or the weekend
before I get a chance to look at this in more detail.

Regards,
Steve Treadwell


--- In sliderule@yahoogroups.com, "sliderulenut" <jayhawk999@...> wrote:
>
> Steve, does yours differ from Clason's or Snodgrass's method?
>
> marion
>

Hi, Steve, In Snodgrass, Slide Rule, one of the teach yourself books
published in England, the folded rule Dualistic is described in section
10 not the Electrical slide rule sectdion. Clason, Delights of the Slide
Rule, was published in 1964. He covers more of the Dualistic rule than
Snodgrass. Both books are available on the Bookfinder used book site.
Clason does a better job of explaining the digit method for folded
scales than Snodgrass.
Marion
--- In sliderule@yahoogroups.com, "dfsmth45" <steve.t123@...> wrote:
>
> Hi Marion,
>
> I am not familiar with Clason - is that available on-line?  As for
Snodgrass, I have only skimmed parts of his book, but it looks like my
method for mixing scales is similar to the one he describes at the end
of the section on "The Electrical Rule".  Well, of course, I suppose it
would have to be similar.  He seems to use "bottom" and "top" rather
than "across" and "same" and only refers to a single inverted R scale
rather than both a CI and CIF scale.  The only place I saw where he
talks about digit counting, he seems to just be using C and D, not
folded scales and tallies based on whether or not the slide sticks out
to the right or left - this works OK for C and D, but not for CI or the
folded scales.  As I say, I have only skimmed it, so I could have missed
something.  I would really need to study his book more before I could
say just how similar my method is.  I have a busy day tomorrow, so it
will be Friday or the weekend before I get a chance to look at this in
more detail.
>
> Regards,
> Steve Treadwell
>
>
> --- In sliderule@yahoogroups.com, "sliderulenut" jayhawk999@ wrote:
> >
> > Steve, does yours differ from Clason's or Snodgrass's method?
> >
> > marion
> >
>



[Non-text portions of this message have been removed]

Example: Evaluate (2¡P8 x 93 x 107 x 46) / (18 x 52 x 29).

Set X to 28D1 and jot down D1
,, 18C2 to X } and jot down /
,, X to 93C1
,, 52C1 to X } and jot down \
,, X to l07C2
,, 29C1 to X } No symbol necessary here.
,, X to 46C1

Under X read 472 in D1, and 1495 in D2.

The symbols when written down in line result in D1 x ; the indication is that
the result is in D1. Approximation gives 46 and the result is 47¡P2.

********
The above example is from on line
Teach Yourself the Slide Rule
http://www.sliderules.info/a-to-z/tys/tys11.htm


The X is the hairline
The C1 and D1 is the C and D we are using
The C2 and D2 is the CF and DF are are using
The slide rule used is the DF(pi) as
"The scales commence at p at the left-hand end of the rule;"......
also the figures.

The example calculate correct result, but with wrong maniuplation.

Set X to 28D1 and jot down D1
,, 18C2 to X } and jot down /
,, X to 93C1

(In this step the wrong intermediate answer is
on the DF (14.28, i.e 14.46 x pi^2 /10
If the hairline is moved to CF93,
the correct intermediate answer will be on D)

,, 52C1 to X } and jot down \

(In this step the correct intermediate answer is
on the D (opposite to CF:1))

,, X to l07C2
,, 29C1 to X } No symbol necessary here.
,, X to 46C1



--- In sliderule@yahoogroups.com, "dfsmth45" <steve.t123@...> wrote:
>
> That second one (wrong manipulation, right answer) is amusing - steps 3 and 4
are both wrong, but cancel out.  Once again, failure because the index on C
doesn't point to the same number on DF as the index on CF points to on D.
>
> Steve Treadwell
>
>
>
> --- In sliderule@yahoogroups.com, "fwonghc" <fwonghc@> wrote:
> >
> > Continue with my previous reply (trap)
> >
> > Wrong calculation but still that can lead to correct answer. Funny?
> >
> > 5 x 5 x 5 x 5 x 5 (answer = 3125)
> >
> > (1) Using DF (sqrt(10)), all are fine.
> > Move hairline to D:5
> > Move CIF:5 under hairline (answer = 25 can be on both D and DF )
> > Move hairline to C:5 (answer = 125 on DF)
> > Move CI:5 under hairline (answer 625 can be on both D and DF)
> > Move hairline to CF:5 (answer = 3125 on D)
> >
> > (2) Using DF (pi), wrong manipulation but still lead to correct answer.
> > Move hairline to D:5
> > Move CIF:5 under hairline (answer on D)
> > Move hairline to C:5 (wrong, = actual answer x 10 / (pi ^ 2) on DF)
> > Move CI:5 under hairline (answer on D)
> > Move hairline to CF:5 (correct answer on D:3125)
> >
> > Correct sequence for DF (pi)
> > Move hairline to D:5
> > Move CIF:5 under hairline (answer = 25 on D)
> > Move hairline to CF:5 (answer = 125 on D)
> > Move CI:5 under hairline (answer = 625 can be on both D and DF)
> > Move hairline to CF:5 (answer = 3125 on D)
> >
> > I personally believe that DF/CF/CIF folded at sqrt(10) is more reasonable.
> >
>