Errors using inadequate data are much less than those using no data at all.

I wish to God these calculations had been executed by steam.

A tool is usually more simple than a machine; it is generally used with the hand, whilst a machine is frequently moved by animal or steam power.

The fatigue produced on the muscles of the human frame does not altogether depend on the actual force employed in each effort, but partly on the frequency with which it is exerted.

It is difficult to estimate the misery inflicted upon thousands of persons, and the absolute pecuniary penalty imposed upon multitudes of intellectual workers by the loss of their time, destroyed by organ-grinders and other similar nuisances.

An object is frequently not seen, from not knowing how to see it, rather than from any defect of the organ of vision.

A young man passes from our public schools to the universities, ignorant almost of the elements of every branch of useful knowledge.