whilft it remains open. But to this I anfwer, that admitting an equal number of rays, or an equal quantity of luminous particles to ftrike the eye at all times, yet if thefe rays frequently vary their na ture, now to blue, now to red, and fo on, or their manner of termination, as to a number of petty fquares, triangles, or the like, at every change, whether of colour or shape, the organ has a fort of relaxation or reft; but this relaxation and labour fo often interrupted, is by no means productive of ease; neither has it the effect of vigorous and uniform labour. Whoever has remarked the different effects of fome ftrong exercife, and fome little piddling action, will understand why a teafing fretful employment, which at once wearies and weakens the body, should have nothing great; these forts of impulfes, which are rather teafing than painful, by continually and fuddenly altering their tenour and direction, prevent that full tenfion, that fpecies of uniform labour, which is allied to ftrong pain, and causes the fublime. The fum total of things of various kinds, though it fhould equal the number of the uniform parts compofing fome one entire object, is not equal in its effect upon the organs of our bodies. Befides the one already affigned, there is another very ftrong reason for the difference. The mind in reality hardly ever can attend diligently to more than one thing at a time; if this thing be little, the effect is little, and a number

a number of other little objects cannot engage the attention; the mind is bounded by the bounds of the object; and what is not attended to, and what does not exift, are much the fame in the effect; but the eye or the mind (for in this cafe there is no difference) in great uniform objects does not readily arrive at their bounds; it has no reft, whilft it contemplates them; the image is much the fame every where. So that every thing great by its quantity must neceffarily be one, fimple and entire.

SECT. XI.

THE ARTIFICIAL INFINITE.

WE have obferved, that a fpecies of greatness arifes from the artificial infinite; and that this infinite confifts in an uniform fucceffion of great parts we obferved too, that the fame uniform fucceffion had a like power in founds. But because the effects of many things are clearer in one of the fenfes than in another, and that all the fenfes bear analogy to, and illuftrate one another, I fhall begin with this power in founds, as the caufe of the fublimity from fucceffion is rather more obvious in the sense of hearing. And I fhall here once for all, obferve, that an inveftigation of the natural and mechanical causes of our paffions, befides the curiofity of the subject, gives, if they are difcover

ed,

ed, a double ftrength and luftre to any rules we deliver on fuch matters. When the ear receives any fimple found, it is ftruck by a fingle pulfe of the air, which makes the ear-drum and the other membranous parts vibrate according to the nature and fpecies of the ftroke. If the ftroke be ftrong, the organ of hearing suffers a confiderable degree of tenfion. If the ftroke be repeated pretty foon after, the repetition caufes an expectation of another ftroke. And it must be obferved, that expectation itself caufes a tenfion. This is apparent in many animals, who, when they prepare for hearing any found, rouse themselves, and prick up their ears: fo that here the effect of the founds is confiderably augmented by a new auxiliary, the expectation. But though after a number of ftrokes, we expect ftill more, not being able to afcertain the exact time of their arrival, when they arrive, they produce a fort of furprife, which increases this tenfion yet further. For I have ob ferved, that when at any time I have waited very earneftly for fome found, that returned at inter vals, (as the fucceffive firing of cannon) though I fully expected the return of the found, when it came it always made me ftart a little; the eardrum fuffered a convulfion, and the whole body confented with it. The tenfion of the part thus increasing at every blow, by the united forces of the ftroke itself, the expectation, and the furprife,

it

it is worked up to fuch a pitch as to be capable of the fublime; it is brought juft to the verge of pain. Even when the caufe has ceafed, the organs of hearing being often fucceffively ftruck in a fimilar manner, continue to vibrate in that manner for fome time longer; this is an additional help to the greatnefs of the effect.

THE VIBRATIONS MUST BE SIMILAR.

BUT if the vibration be not fimilar at every impreffion, it can never be carried beyond the. number of actual impreffions; for move any body as a pendulum, in one way, and it will continue to ofcillate in an arch of the fame circle, until the known caufes make it reft; but if after first putting it in motion in one direction, you push it into another, it can never reaffume the firft direction; because it can never move itfelf, and confequently it can have but the effect of that last motion; whereas, if in the fame direction you act upon it feveral times, it will defcribe a greater arch, and move a longer time.

SECT.

THE EFFECT OF SUCCESSION IN VISUAL OBJECTS EXPLAINED.

IF we can comprehend clearly how things operate upon one of our fenfes, there can be very little difficulty in conceiving in what manner they affect the reft. To fay a great deal therefore upon the correfponding affections of every fenfe, would tend rather to fatigue us by an useless repetition, than to throw any new light upon the subject, by that ample and diffufe manner of treating it; but as in this discourse we chiefly attach ourselves to the fublime, as it affects the eye, we shall confider particularly why a fucceffive difpofition of uniform parts in the fame right line should be fublime,* and upon what principle this difpofition is enabled to make a comparatively fmall quantity of matter produce a grander effect, than a much larger quantity disposed in another manner. To avoid the perplexity of general notions; let us fet before our eyes a colonnade of uniform pillars planted in a right line; let us take our stand in fuch a manner, that the eye may shoot along this colonnade, for it has its best effect in this view. In our prefent fituation it is plain, that the rays from the first round pillar will caufe in the eye a vibration of * Part II. fect. IO,

VOL. I.

T

that