Clocks The first mechanical clock was invented in the early 1300's. With this invention time began to be measured in hours (24 hours equaling a day).
Galileo, an Italian scientist, discovered the pendulum in 1581. The pendulum greatly improved the constant movement of the hands or bell of a clock. The average error with the pendulum varied only by seconds each day. Before this the error was from 10 to 15 minutes a day.
During the 1600's the metallic gear, or toothed wheel, and the use of the screw in assembling the clocks were first used. Eyeglasses or Spectacles Historians are not certain who invented the first spectacles. In the late thirteen century around 1287 paintings first appeared with people wearing or holding spectacles. From these paintings we know that spectacles were invented in Italy.
Around 1300 the Venetian Glassmaker's Guild made regulations on glasses. They made it illegal for glasses to be made with glass lenses in place of the more valuable rock crystal.
In 1352 eyeglasses were only worn by the well educated, very rich noblemen or well read Italian clergy. At this time a monk named Tommaso da Modena documented the church had painted a fresco with an older churchman wearing glasses while looking over an old manuscript.
In 1456 Gutenberg invented the printing press. This created a widespread of books. Once people owned books reading glasses began to be seen in the hands of the common people. These glasses were made with a variety of materials including wood, lead, copper, bone, leather, and even horn. In 1623 the Spanish invented the first graded lenses. This improved the trial and error method of trying on different lenses until one pair helped the wearer to see better. Flush Toilet Sir John Harrington, godson to Queen Elizabeth, made the first flush toilet for himself and his godmother in 1596. He was teased by his friends and never made another one although he and Queen Elizabeth continued to use