The art of meditation may be exercised at all hours, and in all places; and men of genius, in their walks, at table, and amidst assemblies, turning the eye of the mind inwards, can form an artificial solitude; retired amidst a crowd, calm amidst distraction, and wise amidst folly. When DOMENICHINO was reproached for his dilatory habits, in not finishing a great picture for which he had contracted, his reply described this method of study: _Eh! lo la sto continuamente dipingendo entro di me_--I am continually painting it within myself. HOGARTH, with an eye always awake to the ridiculous, would catch a character on his thumb-nail. LEONARDO DA VINCI has left a great number of little books which lie usually carried in his girdle, that he might instantly sketch whatever he wished to recal to his recollection; and Amoretti discovered, that, in these light sketches, this fine genius was forming a system of physiognomy which he frequently inculcated to his pupils.[A] HAYDN carefully noted down in a pocket-book the passages and ideas which came to him in his walks or amid company. Some of the great actions of men of this habit of mind were first meditated on amidst the noise of a convivial party, or the music of a concert. The victory of Waterloo might have been organized in the ball-room at Brussels: and thus RODNEY, at the table of Lord Sandwich, while the bottle was briskly circulating, being observed arranging bits of cork, and his solitary amusement having excited inquiry, said that he was practising a plan to annihilate an enemy's fleet. This proved to be that discovery of breaking the line, which the happy audacity of the hero afterwards executed. What situation is more common than a sea-voyage, where nothing presents itself to the reflections of most men than irksome observations on the desert of waters? But the constant exercise of the mind by habitual practice is the privilege of a commanding genius, and, in a similar situation, we discover CICERO and Sir WILLIAM JONES acting alike. Amidst the Oriental seas, in a voyage of 12,000 miles, the mind of JONES kindled with delightful enthusiasm, and he has perpetuated those elevating feelings in his discourse to the Asiatic Society; so CICERO on board a ship, sailing slowly along the coast, passing by a town where his friend Trebatius resided, wrote a work which the other had expressed a wish to possess, and of which wish the view of the town had reminded him. [Footnote A: A collection of sixty-four of these sketches were published at Paris in 1730. They are remarkable as delineations of mental character in feature as strongly felt as if done under the direction of Larater himself.--ED.]