Engineering drawing was invented by James Watt, the father of the steam engine. Here we see a drawing of a working gear from Mr. Wilkinson?s Bradley Forge Engine. This drawing is dated from 1792 and has a precise scale - 1/8? to the inch
Watt worked during the industrial revolution. This time period marked a change in how machine were built. Instead a craftsman designing and building everything themselves, they would have others build parts and they would assemble the parts. Engineering drawings were invented to specify the parts that needed to be manufactured.
Watt?s drawings are not only beautiful, but he established many of the conventions that we still use today. Notice the use of two related views and the use of dimensioning. Because his drawings were in colors, he used color to indicate materials and functions.
Engineering solved a particular problem. How to specify a manufactured part. They are much more advanced than realistic images of machines. Even today architectural drawings are much more useful than virtual reality walkthroughs.