Cobblestones are stones that were frequently used in the pavement of early streets. "Cobblestone" is derived from the very old English word "cob", which had a wide range of meanings, one of which was "rounded lump" with overtones of large size. "Cobble", which appeared in the 15th century, simply added the diminutive suffix "le" to "cob", and meant a small stone rounded by the flow of water; essentially, a large pebble. It was these smooth "cobbles", gathered from stream beds, that paved the first "cobblestone" streets.
Note that Cobble is a generic geological term for any stone having dimensions between 64–256 mm (2.5–10 inch). A cobbled area is known as a "causey", "cassay" or "cassie" in Scots.
Use in roadways
Cobblestones are typically either set in sand or similar material, or are bound together with mortar. Paving with cobblestones allows a road to be heavily used all year long. It prevents the buildup of ruts often found in dirt roads. It has the additional beneficial advantage of not getting muddy in wet weather or dusty in dry weather. A disadvantage is that carriage wheels, horse hooves and even modern automobiles make a lot of noise when rolling over cobblestone paving. In England, the custom was to strew the cobbles outside the house of a sick or dying person with straw, so as to dampen the sound.
Cobbled streets are highlights in several cycling competitions such as the final Champs-Élysées stage of the Tour de France and the Paris-Roubaix road race as riding upon them is technically more challenging than riding on asphalt.
Cobblestones set in sand have the environmental advantage of being permeable paving, and of flexing rather than cracking with movements in the ground.
Cobblestones were largely replaced by quarried granite setts in the nineteenth century. Cobblestone is often wrongly used to describe such treatment. Setts were relatively even and roughly rectangular stones that were laid in regular patterns. They gave a smoother ride for carts than cobbles, although in heavily used sections, such as in yards and the like, the usual practice was to replace the setts by parallel granite slabs set apart by the standard axle length of the time.