76 ENGLISH MEN OF SCIENCE. [CHAP.
learning were few; they have built up fortunes by perseverance and intelligence, and at the same time have distinguished themselves as original investigators in non-remunerative branches of science. There are other scientific men who possess what is sometimes called quiet energy ; their vital engine is powerful, but the steam is rarely turned fully on. Again, there are others who have fine intellects, without much energy ; but these latter classes are quite in the mic.ority. The typical man of science has been a~ full work from boyhood to old age, and has exuberant spirits and love of adventure in his short holidays, when the engine of his life runs free-temporarily detached from its laborious tasks.
We must be on our guard against estimating a man's energy too strictly by the work he accomplishes, because it makes great difference whether he loves his work or not. A man with no interest is rapidly fagged. Prisoners are well nourished and cared for, but they cannot perform the task of an ill-fed and ill-housed labourer. Whenever they are forced to do more than their usual small