"Science is bound, by the everlasting vow of honour, to face fearlessly every problem which can be fairly presented to it."

"There cannot be a greater mistake than that of looking superciliously upon practical applications of science. The life and soul of science is its practical application."

"Scientific wealth tends to accumulate according to the law of compound interest. Every addition to knowledge of the properties of matter supplies [the physical scientist] with new instrumental means for discovering and interpreting phenomena of nature, which in their turn afford foundations of fresh generalisations, bringing gains of permanent value into the great storehouse of [natural] philosophy."

"You can understand perfectly, if you give your mind to it"

"This time next year,—this time ten years,—this time one hundred years,—probably it will be just as easy as we think it is to understand that glass of water, which now seems so plain and simple. I cannot doubt but that these things, which now seem to us so mysterious, will be no mysteries at all; that the scales will fall from our eyes; that we shall learn to look on things in a different way—when that which is now a difficulty will be the only commonsense and intelligible way of looking at the subject."

"When you are face to face with a difficulty, you are up against a discovery."

"The more you understand what is wrong with a figure, the more valuable that figure becomes."

"I am never content until I have constructed a mechanical model of the subject I am studying. If I succeed in making one, I understand; otherwise I do not."

"First of all I am blamed for crossing the boundary of experimental evidence. This, I reply, is the habitual action of the scientific mind—at least of that portion of it which applies itself to physical investigation. Our theories of light, heat, magnetism, and electricity, all imply the crossing of this boundary."