I don’t know the answer, yet, but I’m certainly glad that they did invent it because cutting the grass is a nightmare without one. Manually cutting grass by the swinging of a scythe, a notoriously tricky instrument to use at the best of times. The lawn mower was invented in the UK in a small village called Thrupp just outside of the town of Stroud. I don’t know if you know the area but it’s very uphill in places so I can see why Edwin Budding did it. Budding originally just intended it to be used on sports pitches (they like a bit of Rugby Union and Cricket there) and it was taking ages to get them nice and level.
The first machine was not motorised, that came a lot later, but it was certainly a better alternative to what had gone before. The main part of the mower was a set of rotor blades that moved as you pushed or pulled. The first one’s did not have the option of attaching them to animals but this soon happened when large lawn owners saw that they could reduce their manual labour costs dramatically.
The push for a motor mower came in the 1920’s. Soon production of the mower and the different types took a pace. You might have one that needs new parts and Briggs and Stratton Parts are the place to get them.