Okay, it's kind of random. The other day on Radio from Hell, Bill asked me if I knew what macadam was, and I didn't. So, I had to rectify that, and this post is the result!
Essentially, macadam is crushed up stone which is then cemented together. It's called macadam after the inventor, John Loudon McAdam. (Paraphrased from Wikipedia) It was a common road surfacing technique in the early 1800's
The Chambers Dictionary of Eponyms relates the following story about McAdams: "It is said that as a small boy McAdam laid out model roads in his back garden - but it was years later, after spending some time in America, that he returned to Scotland, to discover that the roads in the estate that he had bought in Ayrshire were, like most roads, in a poor condition. McAdam set to work to improve the state of the roads, experimenting in Ayrshire and later in Falmouth." McAdams later became the "surveyor general of all British metropolitan roads."
A form of macadamization appears to still be used as a road base, but modern roads are finished with a top layer of asphalt as shown in the image below :
Elements of a modern asphalt road.
© Merriam-Webster Inc.
McAdam was a well known enough figure to inspire the cartoon below
The subject came up on RFH because aacadam was listed as one of the 101 Inventions that Changed the World exhibit at The Leonardo in Salt Lake.
Popular Mechanics also had a similar story about 101 gadgets that changed the world.
Mock-Adam-izing: the Colossus of Roads, a lampoon of John MacAdam, 1827. (2008). In The Bridgeman Art Library Archive
macadam. (2012). In Britannica Concise Encyclopedia.
macadam. (2004). In Chambers Dictionary of Eponyms.
road. (2012). In Britannica Concise Encyclopedia.
Note: These sources were retrieved from the UNT Electronic Resources provided to students; they are not openly available on the internet, but your public library may have access to them through their online subscription databases.