It was his habit, his son tells us, to keep notebooks of things he had observed in his garden or in his walks, and to work them up afterwards into similes for the _Princess_ and the _Idylls of the King_.

Read in the books written by admirers, in which they have been studied and collected (there are several of them) these similes are pleasing enough; in the text where they stand they are apt to have the air of impertinences, beautiful and extravagant impertinences no doubt, but alien to their setting.

In one of the _Idylls of the King_ the fall of a drunken knight from his horse is compared to the fall of a jutting edge of cliff and with it a lance-like fir-tree, which Tennyson had observed near his home, and one cannot resist the feeling that the comparison is a thought too great for the thing it was meant to illustrate.

So, too, in the _Princess_ when he describes a handwriting, "In such a hand as when a field of corn Bows all its ears before the roaring East." he is using up a sight noted in his walks and transmuted into poetry on a trivial and frivolous occasion.

You do not feel, in fact, that the handwriting visualized spontaneously called up the comparison; you are as good as certain that the simile existed waiting for use before the handwriting was thought of.
The accuracy of his observation of nature, his love of birds and larvae is matched by the carefulness with which he embodies, as soon as ever they were made, the discoveries of natural and physical science.
Nowadays, possibly because these things have become commonplace to us, we may find him a little school-boy-like in his pride of knowledge.