Understandable I think. After all, the slide rule is merely an aid to the arithmetic, it doesn't help one design anything. Any calculation can be done long hand, or using a tables book for Squares, Cubes, Logarithms, etc, as we did in high school.
How a Slide Rule works - basic.
- Thread starter Fordman
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Now this is going just too far back in the calculator discussion. 
I've got both Rotring and Faber tech pens with the refillable reservoirs in 0.25, 0.35, 0.5, 0.7 and 1.0mm along with the Faber compass and extension arm. My only tattoo is from dropping the 0.35 pen dead straight on my thumb.
Yep, that is the circle tool I was talking about.
As for pens, when they became available (in the west), my mom received a set of Rotring Isograph but they were not for professionals. She wanted the Rapidograph pens, but that only happened in 79 when we went to Germany and she bought her own. I used them much later at uni and they are still with me. Mind you, they still make them.
They still are around. They are all younger blokes can use.
I have a drawer full of bits of them. When one breaks some of the parts will become a new one. We used to keep them usable with ultrasonic cleaners.
Pen plotters like mine (another antique) use similar pens and had to be watched all through the plot as the ink flow isn't completely reliable.
I have a drawer full of bits of them. When one breaks some of the parts will become a new one. We used to keep them usable with ultrasonic cleaners.
Pen plotters like mine (another antique) use similar pens and had to be watched all through the plot as the ink flow isn't completely reliable.
....on trace required very careful scraping with a razor blade.
You’d always cringe though, that it was going bleed. And what about dragging a set square over wet ink?
I remember there were a few grades of Kalk (tracing) paper, some more tough than others. The very tough ones gave no problems with scraping away ink and re-drawing on top. The lesser grades were a nightmare. The high grade felt thicker.
I was too.
I added paper and linen to make the technique more versatile. We used the blade on everything that had some sort of solidity to it. Final inked work wasn't done on thin tracing paper, or butter paper.
The architects and their draftsmen were masters of the pencil for final work, which I never saw an engineering draftsman really good at.
I added paper and linen to make the technique more versatile. We used the blade on everything that had some sort of solidity to it. Final inked work wasn't done on thin tracing paper, or butter paper.
The architects and their draftsmen were masters of the pencil for final work, which I never saw an engineering draftsman really good at.
It was one of the exams (they had four) for admission to Architecture to draw freehand a perspective at specified angles from three plane views. In three hours. A lot of these exam papers were then displayed in a window facing the street I was walking to get to the Geology dept. Never quite understood how anyone could actually do that. Keep in mind, most of these people were just high school graduates when sitting the exam.
They also sat two Maths exams (calculus and geometry/trigonometry) plus Physics. The degree went in some respectable depth with Static Mechanics.
If you have ever used a graph with log scales (I am certain you have) you already know how to use it. The numbers are nothing more than log tables, base 10. Add numbers on two tables along the rule and you multiply. Subtract two and you divide. It won't do additions. This one being circular, means you can't run off the end. They were very fast if problems were expressed as multiply, divide, multiply, etc.
See https://www.wikihow.com/Use-a-Slide-Rule
Those large rules can do trig, squares and cubes (and roots), simply by changing the scale of the engraving of the logs.
See https://www.wikihow.com/Use-a-Slide-Rule
Those large rules can do trig, squares and cubes (and roots), simply by changing the scale of the engraving of the logs.
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