I can’t look at a setsquare without it reminding me of school maths – I hated it!
Before the introduction of plastic sheets, particularly in ship offices, drawings were produced on tracing linen. This was very fine starched linen and great care was taken to ensure water was kept well clear of it. In winter-time, if you'd forgotten your hankie then a piece was cut off the roll, washed and dried. End of problem!!!!
Could you be careful enough to draw the plans for a locomotive or a ship?
It was actually for marking the different degrees. You would try out some of the French curves and then choose the nearest one to the two parts. Geometry came into our work in the drawing office, so you would use the protractor for accurate angles. It could be used outside of the drawing office too if you needed to check an angle.
You had to buy your own drawing instruments. You didn't really replace them. Later on, there would be audits where they would demand to know that your set square was accurate. There was no way to prove it though. An old man in his seventies used to work in the drawing office and he'd been working from the First World War. He used a set square from that time that was really a minor work of art. It had ladies heads all over it with extraordinarily beautiful Edwardian hair-do's. They were scraped into it with some sort of sharp tool - like etchings. It was quite common to graffiti your drawing tools. People were inclined to scribble their names on and the like.