Since Mr. Tyrrell first broached the idea of a finder, the subject has frequently engaged my attention, and although my own modification of his instrument enabled me with great ease to hit upon any object, however minute, even when using a plain stage to which the original was not adapted, I yet became early aware that a great improvement would be effected if the ivory slip could be altogether dispensed with; as it required, when using high powers, more steadiness of hand for its accurate use than many people are fortunate enough to possess, and as the reading the figures through the microscope was not always easy.
Dr. Wright’s contrivance, which appeared in the same number of the journal as my own, was very satisfactory as far as the individual microscope for which it was used was concerned ; but as no two makers form their instruments exactly on the...
