The object-glass was of four-inch aperture, and when mounted the defining power was found excellent.

My husband was so successful with his telescopes that he went on from smaller to greater, and at length he began to think of devoting himself to optics altogether.

His knowledge of mathematics had led him on, and friends were always ready to encourage him in his pursuits.
"During this time he had continued his teaching at the school in the day-time; and he also taught on his own account the sons of gentlemen in the evening: amongst others the sons of Dr.Wake and Dr.Belcomb, both medical men.

He was only making about 100L.

a year, and his family was increasing.