Improve the consistency of the given text.
Astronomer Robertus Anglicus wrote in 1271 that clockmakers were trying to invent an escapement, but hadn't been successful yet. Most sources agree that mechanical escapement clocks existed by 1300.
Astronomer Robertus Anglicus wrote in 1271 that clockmakers were trying to invent an escapement, but hadn't been successful yet. On the other hand, most sources agree that mechanical escapement clocks existed by 1300.