He gave the contract for casting the high quality optical glass blanks , of a size never before attempted , to the firm of Charles Feil in Paris .
The famous large telescope maker Alvan Clark was in charge of the optical design .
telescope maker gave the contract for casting the high quality optical glass blanks , of a size never before attempted , to the firm of Charles Feil in Paris .
The famous large telescope maker Alvan Clark was in charge of the optical design .