The thought here is no less finely expressed than it is profound. The simile is perfect, if we have the power to separate among the vast variety each state of being from every other, and if the very luxuriance of illustration in the heavens does not bewilder and overpower the mind. It was precisely this discriminating power that HERSCHEL possessed in perfection.
There is a kind of humor in the way he records a change of opinion:
"I formerly supposed the surface of _Saturn's_ ring to be rough, owing to luminous points like mountains seen on it, till one of these was kind enough to venture off the edge of the ring and appear as a satellite."
In 1782 he replies with a certain concealed sharpness to the idea that he used magnifying powers which were too high. There is a tone almost of impatience, as if he were conscious he was replying to a criticism based on ignorance:
"We are told that we gain nothing by magnifying too much. I grant it; but shall never believe I magnify too much till by experience I find that I can see better with a lower power." (1782.)
By 1786, when he returns to this subject, in answer to a formal request to explain his use of high magnifiers, he is quite over any irritation, and treats the subject almost with playfulness:
"Soon after my first essay of using high powers with the Newtonian telescope, I began to doubt whether an opinion which has been entertained by several eminent authors, 'that vision will grow indistinct when the optic pencils are less than the fiftieth part of an inch,' would hold good in all cases. I perceived that according to this criterion I was not entitled to see distinctly with a power of much more than about 320 in a seven-foot telescope of an aperture of six and four-tenths inches, whereas in many experiments I found myself very well pleased with magnifiers which far exceeded such narrow limits. This induced me, as it were, by way of apology to myself for seeing well where I ought to have seen less distinctly, to make a few experiments."
It is needless to say that these experiments proved that from the point of view taken by HERSCHEL, he was quite right, and that his high powers had numerous valuable applications. He goes on to say: