Let the air be darkened

By profound research into the movement of water he has learnt to give his lines of force a logical as well as an expressive significance. In these drawings Leonardo has filled the atmosphere with the cascades and currents which he had studied in moving water. He explains how such atmospheric currents can be made visible. "Let the air be darkened", he says, "by heavy rain whose oblique descent driven aslant by the rush of the winds will fly in drifts through the air like dust." In another passage he writes "A mountain falling on a town will fling up dust in the form of clouds; but the colour of the dust will differ from that of the clouds and beside it the note, "A stone falling through the air leaves on the eye which sees it the impression of its motion, and the same effect is produced by the drops of water which fall from clouds." The scientific care with which these appalling catastrophes are studied has an almost comic effect. "If heavy masses of great mountains fall into vast lakes, a great quantity of water will be flung into the air, and its movement will be in a contrary direction to that of the object which struck the surface, that is to say, the angle of refraction will be equal to the angle of incidence." This fusion between science and fantasy is even more surprising when, some drily scientific observations on the nature of rain are barely legible through the turmoil of universal destruction. Through what strange inhibition did Leonardo attempt to hide from himself the true motive of these drawings? Was it pride in a science which might still look with detachment at the annihilation of humanity; or was it a kind of reserve which prevented him from betraying his innermost feelings in words, even though they were expressed in line? For these drawings come from the depths of Leonardo's soul. In them he has used his scientific knowledge as Michelangelo came to use his understanding of the human body, distorting it to express his sense of tragedy. If in the lovely drawing of a pointing woman he is Prospero, in these Deluges he is Lear:

Blow, winds, and crack your cheeks! rage! blow!

You cataracts and hurricanoes, spout

Till you have drencht our steeples, drown'd the cocks!

You sulphurous and thought-executing fires,

Vaunt-couriers to oak-cleaving thunderbolts,

Singe my white head!

The drawings probably belong to a single period, but some sort of chronological sequence can be established in which the treatment becomes gradually more personal. The earliest is a large study of horsemen assailed by a tornado (12,376), which is like an illustration to the Trattato, and even includes a wind god in the clouds, a conceit far from the spirit of the later drawings. An apocalyptic intention first appears in the pen and ink drawing, 12,388, in which terrified little figures cower beneath a rain fire. Then come drawings like 12,379 where the fury of the elements is released, but the scene is comparatively restricted and within the bounds of possibility. in 12,378 the Deluge is at its height, and we see the motive, often alluded to in Leonardo's description, of a mountain undermined by the gigantic spouts of rain falling on a town and annihilating it. But even more appalling is 12,383, where the Deluge has carried all before it, so that no sign remains of human life or vegetation. This is the climax of the series. There follow several drawings in which Leonardo has grown so absorbed in the elaboration of curvilinear patterns that the scenes lose some of their dramatic force. In 12,380, for example, the linear convention is used so openly that the deluge has become merely decorative; the water-spouts are as powerless as the petals of a chrysanthemum, and the collapsing mountain is made of a child's bricks. Yet compared with the waves of a Japanese screen Leonardo's composition is infinitely richer and more complex. It has a quality of inexhaustible suggestion only possible in the work of a man to whom the subtlety of natural appearances was perfectly familiar.

On grounds of style and spirit, these drawings must belong to the uneasy years of residence at Rome. During that period the Pope seems to have consulted him on a scheme for draining the Pontine marshes, and in a drawing at Windsor, representing a bird's-eye view of the land in question, the treatment of hills and trees is very similar to the foreground of the deluges. It is suggestive that in the margin of that description of a tempest which most closely conforms to the drawings is the note, "The wave of the sea at Piombino is all foaming water"; for it was at Piombino that Leonardo had been employed in another great effort to drain marshy land.