Slide Rule

[Suzy_A]

Hi All,

I still use a slide rool.

You are still required to know how to use one for many aviation exams. Have a look at http://www.casa.gov.au/fcl/exams/cyber/material.htm

"Nav Equipment
When permitted, the term 'Nav equipment' includes:

Dividers
Compass
Protractor
Ruler (or straight-edge)
non-electronic 'aviation wind triangle and circular slide rule' computer. eg Jeppesen Sanderson CR or other brands of similar type or a manual slide rule"
"(Electronic flight planning device/computer is NOT permitted in place of Jeppesen CR or a manual slide rule)"

....

"The ATPL exams"
(Airline Transport Pilot Licence - ie to fly a 7X7 etc for Qantas etc)


"6. APLA
Required/to be supplied by candidate
Navigation equipment
B727 Performance and Operating Handbook
CAO 20-95.2 "

[Nordo]

I've just come across this thread and read all the posts. I reckon I could list the age of all the poster's based on their comments (a la Henry Higgins).

I remember, and used almost everything that has been mentioned (except the Curta Peppermill).
We had milk delivered bulk into a billy. My parents had a stack of 78s. I was an ink monitor in my class. I owned a Commodore 64. I used 4 figure logs and trig tables in high school, which later extended to 8 and 10 figure tables at work (survey).
I designed a 20 storey building (200 Queens St, Melbourne) using a 2 sided slide rule and 8 figure log/trig tables.
Later on I owned an HP45 (could never trust using the "stack" memory).

I remember working in an engineering office during school holidays. They had a calculating machine that was wheeled around from desk to desk. You pushed a few things, then pulled the big lever at the end - like the old poker machines.
The worst thing in a drawing office was the pens . You put a drop in ink between two blades (resembling a pair of tweezers), then turned a screw until the pen made a line just the right thickness - but of course by then the ink had dried up and you had to start all over again .

[Dujon]

Ha, ha, Nordo. I used those yonks ago when I did tech. drawing. Mind you it was not often and, if memory serves, 'twas only experimentally rather than a course requirement (we generally used various pencil grades and cartridge paper).

Do draughtsmen (sexist, I know) still use linen paper? Occasionally my father would bring home a few sheets of the stuff - presumably drafts which were no longer required. A bit of a soaking and you finished up with a lovely sheet of linen. My grandmother, who was a fantastic seamstress, put them to all sorts of good use.

Oh yes; shouldn't that be 'Enry 'Iggins?

[mickoking]

I was doing a course in the RAAF in 1988 and we were taught how to use the slide rule there. But as soon as I graduated I used a calculator and totally forgot how to use a slide rule. They occasionally pop up in Op shops.

[Suzy_A]

Originally Posted by Nordo

I've just come across this thread and read all the posts. I reckon I could list the age of all the poster's based on their comments (a la Henry Higgins).
...a stack of 78s. .....a Commodore 64. I used 4 figure logs and trig tables ...... an HP45 (could never trust using the "stack" memory).

I remember working in an engineering office during school holidays. They had a calculating machine that was wheeled around from desk to desk.

Hey!

How old do you think we all are!

I've still got some 78s - they don't do everything on CDs! (Actually, I don't anymore - my older sister turned them all into ashtrays and clocks...) And I had a C64 - I still use an Amiga monitor as a TV. And I've used a HP45 - I worked in a hospital (not that long ago) where one was still used and a guy that lives near my mother has a PDP11 in his shed. For those that don't know, a PDP 11 was a computer (one up from a mini and one down from a mainframe) that had... 512 KB and ran at .. 4 MHz I think.... Fast for them daze - it would take about 20 users at once. And when I started uni, there was a Perkin Elmer 8/32 - with a whole 1 MB of magnetic core memory! It was fondly known as the 'Elmer Fud'. When the power went down, you'd just wait and when it started up again, everything was still there! That was the great thing about MCM. MCM, for those that don't know, is a type of memory that was made by in India or Afganistan by nimble little carpet weavers that wove mm sized magnetic cores onto wire lattices. They held the memory by being magnitised N or S. If the electrickery went off - they held their polarity, and so when the computer booted up again, everything wuz still there.

By the way, I met someone a couple of years back who was a .... can't remember what their job title was.... They are retired now, but they were a professional maths calculator who worked at Myers. At the end of the day, they were given the list of sales and went through and calculated - in their head - the day's sales. Prior to that they worked on ballistic (artillery) tables but were replaced by a computer with 512 B (that's bytes...) and used about a MW.

[xelasnave]

Hey Suzy I owned a real estate office and at the end of the day I could could calculate the number of sales our sales staff of 3 had made, it was easy unless they each made a sale
alex

[Nordo]

When I was in my early teens my father bought me "The Trachtenberg (?)System of Speed Maths". I only gave it a cursory glance, but it had all these nifty ways of doing large heavy calculations in your head. I couldn't see how I could impress girls with it so I lost interest.
There was a TV show where competitors had to be the quickest to write down the answer to large calculations. The better ones would be writing the answer down before the host had finished reading the question.
Perhaps we shouldn't be bringing old TV shows into the discussion , but I used to love "Why Is It So?" with Julius Sumner Miller. I was only a kid, but it was still my favourite show.

[xelasnave]

When I got my hands on a calculator I pulled it apart and came up with the idea they could be worn on the wrist, I rebuilt it to fit and worn so. I went to a patent attorney to patent it and was told the idea was not novel enough to get the patent, so I gave up on the project.
Moral of that story is if your expert does not give you the advice you want to hear find one that does.
alex

[Geoff45 (Geoff)]

Originally Posted by merlin8r

As for biro's, here's a great analogy. NASA spent millions of dollars developing a pen that would work in zero gravity. The Soviets used a pencil.

Clear skies,
Shane

Unfrortunately, this is one of those urban myths that should be true, but isn't. For the real story see http://www.snopes.com/business/genius/spacepen.asp

BTW I still have 2 slide rules, both made by Faber-Castell
Geoff

[Omaroo (Chris Malikoff)]

Originally Posted by ghsmith45

Unfrortunately, this is one of those urban myths that should be true, but isn't. For the real story see http://www.snopes.com/business/genius/spacepen.asp

It's a great story. I used to collect FSP's. I have lots of them in all different manner of styles and shapes. I've had them for years and am yet to have one run out. I've also yet to test any myself in +150C or -150C temps or in lieu of gravity. Maybe one day!

[Suzy_A]

[quote=Nordo]...but it had all these nifty ways of doing large heavy calculations in your head. I couldn't see how I could impress girls with it so I lost interest.
quote]

Reminds me about Nikola Tesla - when he was 12 or so, his maths teacher (who hadn't prepared the lesson) told the class to work out the answer of 1+2+3+4+....+100, thinking it would take them an hour or so.

It took Tesla about 30 seconds - and he did it in his head.

0+100 = 100
1+99=100
2+98=100
...
...
...
49+51=100

so there are 50 pairs of X+Y = 100, so that equals 5000. And then there is 50 left over, so the total is 5050!

Easy!

[johnno]

Hi All,

I have never used,But own a couple of slide rules,from my father's estate,

I do remember being left handed in school,and being made to change over,because"You will smudge your work,when you use the ink well"

I was born in 1949.

Regards.John

[Nordo]

Nikola Tesla was one of the world's most brilliant inventors, and least known.
As a kid I always wanted to build a tesla coil.
Tesla invented many things we take for granted (eg brushless electric motors).
He wanted to distribute electricity not with wires, but electromagnetic waves - hence the tesla coil. The tesla coil I made plans was a high voltage coil orientated vertically. You could show off it's properties by doing various "tricks" including holding a fluorescent tube in the same room and it would light up.
Doing a google search for Nikola Tesla or tesla coil, will give you hours of fascinating reading.

[Geoff45 (Geoff)]

[quote=Suzy_A]

Originally Posted by Nordo

...but it had all these nifty ways of doing large heavy calculations in your head. I couldn't see how I could impress girls with it so I lost interest.
quote]

Reminds me about Nikola Tesla - when he was 12 or so, his maths teacher (who hadn't prepared the lesson) told the class to work out the answer of 1+2+3+4+....+100, thinking it would take them an hour or so.

It took Tesla about 30 seconds - and he did it in his head.

0+100 = 100
1+99=100
2+98=100
...
...
...
49+51=100

so there are 50 pairs of X+Y = 100, so that equals 5000. And then there is 50 left over, so the total is 5050!

Easy!

Same story about Gauss when he was 6. Actually there is a very simple formula:
sum of 1st n integers = 0.5*n*(n+1).

[Gargoyle_Steve (Steve)]

I appear to have been born in a gap between most of the rest of you ..... meaning I was born in 1964.

I never had or used a slide rule at school, and neither did we have ink wells, biros were ok even at primary shchool from about grade 3 or 4 onwards.

There was no such thing as a computer at primary school, and at high school we had a PDP-11 (card reader data entry only, lead pencil not punch cards - if you've done that you know how bad it can be)


There was also a "compact" 4k desktop type computer, whose brand escapes me at present, it was a rather unusual brand, but similar to early Tandy, etc units.

We had bottled milk deivered in Bisbane, but on weekends up to Gympie (reasonably large town) to visit my Aunt & Uncle the milk there (in town) was still delivered fresh to your jug / cannister / whatever.

Mum and Dad still had some 78's around, and of course we had a turntable that played them - does anyone know what the hell the 16 speed was ever used for?? Apart from making Elvis, Frank Sinatra, etc, sound very weird - which I did often.

Dogs roamed the streets freely - our street had 12 houses, and 14 dogs - they hung out mostly in one large group, with a couple of "outsiders" - and no one got bitten (except dogs) and no dog catchers ran around trying to take them away to have them put down.

I remember at primary school when the price of a sausage roll went from 5c to 8c in one jump - parents screamed!

I remember when lollies were at most 1c each, you could get a stomach ache for 30c, if you had 30c that is. Those red raspbery lollies were still 3 for a cent .. ggez I ate a lot of those. Rainbow monsters were the dearest - 3 for 2 cents, how shocking! Around this time I think I got 50c a week pocket money, and was damned pleased to get that too.

Good days .... good memories!

[Omaroo (Chris Malikoff)]

Originally Posted by Gargoyle_Steve

I remember at primary school when the price of a sausage roll went from 5c to 8c in one jump - parents screamed!

I remember when lollies were at most 1c each, you could get a stomach ache for 30c, if you had 30c that is. Those red raspbery lollies were still 3 for a cent .. ggez I ate a lot of those. Rainbow monsters were the dearest - 3 for 2 cents, how shocking! Around this time I think I got 50c a week pocket money, and was damned pleased to get that too.

Good days .... good memories!

LOL!! Memories!

Yup - I remember the time when Big Ben meat pies went up from 12 to 15 cents. It nearly broke the bank!

'Stomach ache for 30c' ... yep - I think they were called "fruit cocktails" if I remember rightly. Being able to somethimes (if you saved up)pull out a two-dollar note in the school lunch time canteen line was special.... (especially when you got ten cents a week pocket money)

[matt]

Hmmmmmmmm

Appears I'm also one of those "in between" generation types. Born in '67.

My first real memory of anything computerish was the Sinclair ZX80.

I was "lucky" enough to receive the ZX81 for Xmas the following year.

I say "lucky" coz it has an on-board memory of a laughable 1K!!!

You actually had to spend more money to acquire a bulky 16K plug-in unit which really changed your life