Apparent solar time grew less useful as commerce increased and mechanical clocks improved. Mean solar time was introduced in almanacs in England in 1834 and in France in 1835. Because the sun was difficult to observe directly due to its large size in the sky, mean solar time was determined as a fixed ratio of time as observed by the stars, which used point-like observations. A specific standard for measuring "mean solar time" from midnight came to be called Universal Time.
Apparent solar time grew less useful as commerce increased and mechanical clocks improved Mean solar time was introduced in almanacs in England in 1834 and in France in 1835 Because the sun was difficult to observe directly due to its large size in the sky mean solar time was determined as a fixed ratio of time as observed by the stars which used point-like observations A specific standard for measuring "mean solar time" from midnight came to be called Universal Time