The Archimedean lawn mower was designed in 1869 by Amariah Millar Hills, an American who had a factory in Connecticut. He was the first American to be granted a patent for a lawn mower, in 1868.
The name of the mower comes from the shape of the cutting cylinder, which is like an Archimedean screw in being spiral or helical in profile. The mower was innovative through its compact and lightweight design compared with mowers from other manufacturers.
The early Archimedean machines had a solid cast cutting cylinder with just two blades. A similar arrangement could be found on other designs of the period. The mower was later manufactured for the UK market by Williams and Company of London. This company was the original British agent for Hills and its revised design featured a more conventional arrangement of open blades. This comprised a single casting to which the blades were bolted. The spindle or axle for the cylinder was integral to the casting. Like many mowers of the period the Archimedean had gears to transmit power from the rear roller to the cutting cylinder.
The pioneers of the lawn mower settled upon the basic configuration of the hand roller machine very early on and it has not changed much over the years. However, in the early days there were many different styles and types of handle. On the Archimedean, for example, a T shaped handle was used that could move freely up and down so that the cross piece was always at a convenient height for the user whatever the aspect of the mower. This design helped keep the weight of the mower down but a major disadvantage was that the handles could not be pressed down to raise the front roller of the mower. This is useful when manoeuvring in tight spaces and turning corners as it makes it much easier to steer the mower. This may explain why roller mowers tend to have fixed handles with hand grips on the end of two side shafts.
Another oddity of the Archimedean's design was the use of small skids at the front of the mower instead of wheels. This was presumably not considered a success because later models reverted to using wheels. In any case the use of wheels or skids avoided the need for a front roller which meant the mower could be used to cut longer grass. This is because the grass can enter the cutting mechanism without being pushed down and out of the way by the front roller.
The Archimedean was imported into the UK in some numbers, mostly through the company's British agent, Williams and Company of London. It was advertised with and without a grass box. The company claimed that allowing the cuttings to fall back onto the lawn (by not using the grass box) and form a mulch had many benefits for the health of the lawn. These included returning nutrients back to the soil and retaining moisture in dry summer periods. This may have been the first lawn mower to be sold with these benefits in mind and it is interesting to see that the same arguments are still being used as a selling point in the 21st century.
Examples of the Archimedean are extremely unusual and much sought after by collectors. The example shown in the images here belongs to the Hall & Duck Trust.
There is a brief biography of Amariah Hills here on a separate site.