If you own a home, and that home has grass out in front of (or behind) it, then summer is lawn-mowing time.
Lawns as we know them date back to the 1700s, when British estates began to feature lawns that flowed away from the house into the surrounding woods. The custom carried over to North America, where we certainly had plenty of room for them. Unless you were willing to let sheep graze on them, though, the only way to keep them short was with a sickle or scythe.
Then, in 1830, English engineer Edwin Beard Budding, inspired by a machine he had seen at the local cloth mill which used a cutting cylinder to shear the nap off of velvet, invented the first lawn mower. His cast-iron design featured a large rear roller that transmitted power via gears to a cutting cylinder in the front.
The next major technological advance was the side-wheel mower, which had wheels on either side of the cutting cylinder that directly drove it. Invented around 1870 by Elwood McGuire of Indiana, the new design was easy to push and inexpensive. By 1885 the U.S. was building 50,000 a year and shipping them all over the world.
As the first lightweight gas engines and small steam engines became available in the 1890s, the first power mowers were developed. But power mowers really moved to the forefront with the invention in 1940 of the rotary power mower by Leonard Goodall of Missouri. Its blades, rotating parallel to the ground, made it easier to cut long grass and easier to get a uniform cut. It was a product whose time had come: following the Second World War, the suburbs, and their associated lawns, blossomed.
Regular cutting reduces the workload on grass’s root system. Tall stems and blades require more water and nutrients. As well, lawns that are cut regularly are thicker, and thus more resistant to disease and weeds, because losing blades to the mower makes the grass grow more blades in an attempt to get more sunlight.
Mower technology recently took another step forward with the development of the first lawn-mowing robots. There are several makes available. Thousands of Robomowers, built by Friendly Robotics of Kadima, Israel, and marketed by Toro under the name iMow, have been sold over the past five years. Electrolux’s Husqvarna division also has a robotic lawn mower, called the Auto Mower.
The perimeter of the lawn is first marked out by a wire. Within that perimeter, the robomower typically follows a random pattern. That means it doesn’t necessarily mow the lawn with the greatest possible efficiency, and that means that it may run out of battery power before it’s finished, especially in a large yard. As well, robomowers sometimes flatten grass with their safety guards. When that happens, some blades don’t get cut, and those blades can eventually grow too tall for the robot mower cut the next time.
There is at least one more sophisticated robomower designed for large grassy areas like golf courses. Researchers at Carnegie Mellon University, with sponsorship from Toro, have come up with the Automated Turf Management System, which uses a sweeping laser rangefinder to build up a 3D map of the area in front of the mow and detect obstacles as small as a golf ball. A GPS system and inertial data helps the robot find its way around a defined area, such as an athletic field or fairway.
Robots are all well and good, but wouldn’t it be even better if you didn’t have to mow your grass at all?
Researchers at the Salk Institute for Biological Studies in San Diego announced last week that they’ve mapped a hormone-signaling pathway that regulates plant height. They hope to learn to use this pathway to specify the height of plants.
The hormones in question are brassinosteroids, which appear to be crucial to plant growth. Plants without them, for instance, are tiny, infertile dwarves. By manipulating brassinosteroid expression in plans, scientists may someday be able to not only keep grass short and green, but (ultimately more important, of course) also develop sturdier, more fruitful crop plants such as rice, wheat, soybeans, and corn.
Imagine a spray-on gene therapy that would keep your grass short and green, your hedge perpetually trimmed, and your lilac bushes from attempting to eat your house, while also helping you grow bigger ears of corn and richer, redder tomatoes in your garden.
Sounds great, doesn’t it?
Unless, maybe, you’re a lawnmower manufacturer.
1 comments
Really great post. FYI, I’ve got a whole blog devoted to home robots, including Roomba, Scooba, and Robomowers.
Check it out:
http://robotstocknews.blogspot.com