Christie's, the oldest fine art saleroom in the world, was founded by James Christie on 5 December 1766. Born in Perth in 1730, James Christie first became a midshipman in the Royal Navy, but resigned his commission before he was 20 and became an auctioneer in Covent Garden. At the age of 33 he set up on his own in modest rooms in Pall Mall, moving in 1779 to 125 Pall Mall, next door to Gainsborough.

The picture sales which the firm of Christie's held during the 18th and 19th centuries were the basis for the present collections in museums from Berlin to Boston, and from London to Leningrad.

The Boston Massacre was an incident in American history, on March 5, 1770, when British soldiers fired on a crowd in Boston, resulting in the death of five persons. The "massacre" was the culmination of a series of encounters between British troops quartered in the city and Bostonians who, by continual harassment, sought to force their removal.

Headshrinking is the process whereby a human head trophy is reduced in size. The Jivaro Indians of the tropical forest area of eastern Ecuador are the best known of the groups that practice headshrinking. Shrunken heads (tsantsas) are made and kept by the Jivaro as part of their blood feuds with neighboring groups and the religious and spiritual complex associated with these feuds.

Headshrinking is only a specific part of the more widespread practices of headhunting and trophy taking. To the Jivaro, taking a head avenges a death and provides the killer with his victim's soul- that is, with greater strength. Several additional souls may be acquired by a man in this way in the course of a lifetime. Heads were taken and preserved in such widespread parts of the world as Indonesia, Oceania, and Central Africa, as well as parts of Central and South America.

Lipreading is understanding spoken words by observing how a speaker's lips shape sounds rather than by hearing them. It provides many deaf people with a medium of communication and is an important part of the education of the deaf. In learning lip-reading the deaf watch and touch the face of the instructor who is speaking. Children who were deaf before learning to talk are taught to make sounds and words by imitating, usually before a mirror, the lip and facial motions they have thus observed. This technique for teaching the deaf is called the oral method. It is superior to the traditional sign language, which allows a person to communicate only with those who know that system. Lipreading allows communication with anyone whose face can be observed.

A vernier is a short scale that slides on a longer scale and indicates subdivisions of the longer scale. The principle of the vernier can be applied to both linear and angular measurements. The scale was invented in about 1630 by the French mathematician Pierre Vernier.

Clydesdale in Lanarkshire, Scotland, is the valley of the upper reaches of the Clyde River. It is about 50 miles (80 km) long. The district is chiefly agricultural and is noted for its orchards and coal and iron mines. Clydesdale is the name of a breed of heavy draft horse that was developed here in the early 18th century. The horses are muscular in build and have a long, easy stride.

Mineral oil is any oily liquid of mineral origin, as distinguished from oils of animal or vegetable derivation. Aside from the so-called essential oils, which are of varied composition and are largely employed as flavors, animal and vegetable oils are primarily glycerine esters of fatty acids.

Concrete is one of the most useful building materials ever developed by man. It is strong, long-lasting, fairly cheap to use, and easy to handle. It is not harmed by fire, water, weather, or heavy pressures. Huge dams, bridges, and skyscrapers, as well as highways, homes, and airport runways, are built of concrete.

Concrete is made from Portland cement, water, and sand, gravel, or crushed stone. The materials are measured and mixed together to make concrete. After mixing, the concrete can be given any shape that is wanted by placing it in molds that are called forms.

April Fool's Day is the first of April, also known as All Fools' Day. On this day practical jokes are played, such as sending a friend on a fool's errand or duping him into doing or be­lieving something absurd.

Although the practices of the day are of ob­scure origin, they are thought to have arisen with the celebrations of the vernal (spring) equinox. Many folklorists believe that the custom of playing someone for a fool on this day was begun in France in 1564 with the adoption of the reformed calendar. A person who resisted changing New Year's Day from April 1 to Jan­uary 1 was victimized by pranksters on April 1 and became known as poisson d'avril (April fish).

Bandana, or bandanna, is a silk or calico handkerchief with a printed pattern of spots and diamonds. Bandana handkerchiefs were originally made in India, but are now manufactured in England. The handkerchief is first dyed one colour, and then placed between leaden plates, on which the pattern has been cut out, and put into a powerful Bramah-press, when the colour is discharged by means of a bleaching liquid, and the spots are left white on the dyed background.