Richard Cowen’s Chapter Eight: Leaving the Water – images – curent page , , to , , years ago Eurypterids, otherwise known as sea scorpions. Wikipedia Late Ordovician survivals and extinctions: There were no land animals and extinctions were confined to water life. There were two distinct extinctions roughly a million years apart.

The HyperTexts English Poetry Timeline and Chronology English Literature Timeline and Chronology World Literature Timeline and Chronology This is a timeline of English poetry and literature, from the earliest Celtic, Gaelic, Druidic, Anglo-Roman, Anglo-Saxon and Anglo-Norman works, to the present day.

Renaissance Turret Clock, German, circa Spring driven Matthew Norman carriage clock with winding key Clockmakers developed their art in various ways. Building smaller clocks was a technical challenge, as was improving accuracy and reliability. Clocks could be impressive showpieces to demonstrate skilled craftsmanship, or less expensive, mass-produced items for domestic use. The escapement in particular was an important factor affecting the clock’s accuracy, so many different mechanisms were tried.

Spring-driven clocks appeared during the 15th century, although they are often erroneously credited to Nuremberg watchmaker Peter Henlein or Henle, or Hele around This resulted in the invention of the stackfreed and the fusee in the 15th century, and many other innovations, down to the invention of the modern going barrel in Early clock dials did not indicate minutes and seconds.

A clock with a dial indicating minutes was illustrated in a manuscript by Paulus Almanus, and some 15th-century clocks in Germany indicated minutes and seconds. Some of the more basic table clocks have only one time-keeping hand, with the dial between the hour markers being divided into four equal parts making the clocks readable to the nearest 15 minutes.

Other clocks were exhibitions of craftsmanship and skill, incorporating astronomical indicators and musical movements. The next development in accuracy occurred after with the invention of the pendulum clock. Galileo had the idea to use a swinging bob to regulate the motion of a time-telling device earlier in the 17th century. Christiaan Huygens , however, is usually credited as the inventor.