| Harvard bricks |
During the medieval times, most bricks were made without molds. The clay was mixed with water in a shallow pit called a pug, until it reached the right consistency. Then it was cut into shape for bricks. The mixing was done with the feet. In later times, a horse was often hitched to a pole and walked in circles as another pole in the pug mixed the clay. After the bricks were shaped and sun-dried, they were stacked for firing. Wood was piled neatly all around the bricks and a fire was kept burning until the bricks were thoroughly baked. The outer bricks were often coal black and inner ones rich reds and oranges. This method was employed by descendants of the French brickmakers at Exeter, N. H., where the bricks for Blessed Trinity were made. (They even used antique-type tools for the process.) These "Harvard" bricks are very hard and impervious. They were laid in a thick, soft mortar bed as in the medieval fashion. This produced a solid bond between brick and mortar and explains why there are so few hairline cracks -- so frequent in modern brickwork. Because of the method of making bricks without molds in medieval times, the shape of the bricks was varied: some regular and some irregular. This was further complicated by the possibility of bricks shifting during the firing process. (This accounted for misshapen bricks.) To use all the bricks made, medieval bricklayers had quite a challenge on their hands. As far back as Roman times, bricklayers introduced patterns into the floors and later into the walls. (It was called "opus spicatum.") While examples of it can be found in Rome, Ravenna and Pavia, it was well-accepted in northern Italy from the 8th to the 15th century. The origin of this method appears to be a simple solution for using odd-shaped bricks, as well as large pebbles, stones, and chippings of all kinds in the same construction. In time, some guilds used designs as trademarks, and individual bricklayers worked their own patterns here and there into the construction. The walls of Blessed Trinity are two feet thick. To produce solid, well-bonded walls, the bricks are often crossed and laid lengthwise into the wall, with the ends or "headers" exposed. Because of the many odd shapes and variation in colors, the modern bricklayers were unfamiliar with a method for laying these bricks, Chester Oakley, the architect, personally laid the first few courses of brick with the bricklayers. After they learned the technique, they were allowed to work in their own designs. The herring- bone design on the exterior of the apse and the small designs within the exterior arches of the facade and nave are based on definite historical precedents. The various shapes and colors and patterns are especially interesting when the snow filters in between them or when the bright sun creates contrasts. Many of the Senior residents of the area proudly point out these bricks, because some of them bought bricks as children at five cents apiece. As one of them said: "There are few memorials as enduring as a church building." |
|
|