Not to be confused with
Carrom.
Carom billiards, sometimes called carambole billiards or simply carambole and, in some cases, used as a synonym for the game of straight rail from which many carom games derive, is the overarching title of a family of billiards games generally played on cloth-covered, 5 by 10 foot (approximately 1.5 × 3 m) pocketless tables, which often feature heated slate beds. At its simplest form, the object of most carom games is to score points or "counts" by caroming one's own cue ball off both the opponent's cue ball and the object ball(s) on a single shot. The invention as well as the exact date of origin of carom billiards is somewhat obscure but is thought to be traceable to 18th century France.
There are a large array of carom billiards disciplines. Some of the more prevalent today and historically are (chronologically by apparent date of invention): straight rail, cushion caroms, balkline, three-cushion billiards and artistic billiards. There are many other carom billiards games, predominantly intermediary or offshoot games combining elements of those already listed, such as the champion's game, an intermediary game between straight rail and balkline, as well as games which are hybrids of carom billiards and pocket billiards, such as English billiards played on a snooker table and its descendant games, American four-ball billiards, and cowboy pool.
Equipment
Cloth
The Family Remy by Januarius Zick, c. 1776, featuring billiards among other parlour activities.
Cloth has been used to cover billiards tables since the 15th century. In fact, the predecessor company of the most famous maker of billiard cloth, Iwan Simonis, was formed in 1453. Most cloth made for carom billiards tables is a type of baize that is dyed green, and is made from 100% worsted wool, which provides a very fast surface allowing the balls to travel with little resistance across the table bed. The green color of cloth was originally chosen to emulate the look of grass, and has been so colored since the 16th century. However, the color also serves a useful function, as humans have a higher light sensitivity to green than to any other color, allowing play for longer periods of time without eye strain.
Balls
A standard set of
carom billiards balls (61.5 mm [2
7⁄
16 in] diameter), including a red
object ball, a plain white
cue ball, and a dotted cue ball for the opponent. Some games use an additional object ball.
Modern billiard balls are made from phenolic resin or other highly resilient plastics, are normally 61.5 mm (27⁄16 in) in diameter, weigh between 205 and 220 grams (7.23 – 7.75 ounces; 7.5 is average), and are significantly larger and heavier than their pocket billiards counterparts. While UMB, the International Olympic Committee-recognized world carom billiards authority, permits balls as small as 61.0 mm (approximately 23⁄8), no major manufacturer produces such balls any longer, and the de facto standard is 61.5 mm. The three standard balls in most carom billiards games consist of a completely white cue ball, a second cue ball with typically a red or black dot on it (to aid in differentiation between the two cue balls), and a third, red ball. In some sets of balls, however, the second cue ball is solid yellow. Both types of ball sets are permitted in tournament play.
Billiard balls have been made from many different materials since the start of the game, including clay, wood, ivory, plastics (including celluloid, Bakelite, crystalate, and phenolic resin) and even steel. The dominant material from 1627 until the early- to mid-twentieth century was ivory. The search for a substitute for ivory use was not for environmental concerns but based on economic motivation and fear of danger for elephant hunters. It was in part spurred on by a New York billiard table manufacturer who announced a prize of $10,000 for a substitute material. The first viable substitute was celluloid billiard balls, invented by John Wesley Hyatt in 1868, but the material was volatile and highly flammable, sometimes exploding during manufacture.
Billiard cues
George Sutton tobacco card, c. 1911. The game shown is
balkline.
Billiard cues have specialized refinements making them different from the typical pool cue which many people are more familiar with. Such cues tend to be shorter overall, with a shorter ferrule, a fatter butt, a wooden pin joint, a fast taper, and a smaller tip diameter as compared with pool cues. These features make the cue significantly stiffer, which aids in handling the larger and heavier billiard balls as compared with pool cues, but more importantly, act to reduce deflection. Deflection, sometimes called squirt, may be defined as displacement of the cue ball's path away from the parallel line formed by the cue stick's direction of travel. It is a factor that occurs every time english (sidespin) is employed, and its effects are magnified by speed. In some carom billiards games, deflection plays a large role because many shots require extremes of english, coupled with great speed; a combination typically minimized as much as possible, by contrast, in pocket billiards.
Heated slate
The slate bed of billiard tables are often heated to about 5 °C/9 °F above room temperature, which helps to keep moisture out of the cloth to aid the balls rolling and rebounding in a consistent manner, and generally makes a table play faster. A heated table is required under international carom rules and is an especially important requirement for the games of three-cushion billiards and artistic billiards. Heating table beds is an old practice. Queen Victoria of England (1819–1901) had a billiard table that was heated using zinc tubes, although the aim at that time was chiefly to keep the then-used ivory balls from warping. The first use of electric heating was for an 18.2 balkline tournament held in December 1927 between Welker Cochran and Jacob Schaefer, Jr. The New York Times announced it with fanfare: "For the first time in the history of world's championship balkline billiards a heated table will be used..."
and speed) using various types of 
