Leonardo da Vinci, Pathfinder of Science

by Henry S. Gillette

The year was 1480. The monk represented the monastery of San Donato a Scopeto near the Porta Romana, just outside Florence. Leonardo shook his head slowly at the terms of the commission. The painting had to be completed in thirty months at the most. Moreover, he must pay for his own colors and even—Leonardo looked up as if to protest but resumed reading—even pay for any gold or gold leaf he might use. Nevertheless, it was an opportunity, and Leonardo needed work. Since the papal war had ended, he had not received any commissions—and his skill at military engineering was still too unknown to have won him recognition.

Although Lorenzo de’ Medici was a great supporter of the arts and sciences, he had not granted Leonardo any of his patronage. In Lorenzo’s court were many men with much book-learning but little talent. They guarded their positions jealously and kept the way to Lorenzo barred to any applicant whom they did not like. Of them, Leonardo wrote in his notes: “They strut about puffed up and pompous, decked out and adorned, not with their own labors, but by those of others, and they will not even allow me my own. And if they despise me who am an inventor, how much more blame be given to themselves, who are not inventors but trumpeters and reciters of the work of others?”

In accepting the commission to paint the altarpiece, Leonardo hoped to attract attention to himself. Perhaps then Lorenzo might welcome him to his court and grant him patronage. So, with his usual thoroughness, Leonardo set about the task of preparing an Adoration of the Magi—a favorite subject of that time. This was to be a picture of the Holy Family surrounded by the three wise men from the East, shepherds and animals, old and young, rich and poor, paying their adoration to the Christ child.

Since he wanted his subjects perfect in every detail, Leonardo set about drawing countless youths, old men, sheep, oxen, horses, and donkeys. In a separate drawing for the background, he worked out with mathematical mastery the problems of perspective, that is, drawing objects to make them appear three-dimensional and either close or far away in space. In addition, he made studies for the composition of the whole picture—studies in which his knowledge of geometry was used to heighten the excitement of this great religious subject.

Leonardo’s hygrometer.

Among these sketches that Leonardo made for his “Adoration of the Magi” is a page on which appears an inspiration for one of his greatest masterpieces—a drawing of the “Last Supper.” And on this same page is another drawing—one of a hygrometer. A hygrometer is an instrument for measuring the amount of moisture in the air. Leonardo’s design consists of a simple, graded disk with a balanced pointer, weighted at one end with sand and at the other with a sponge or some salt. As the sponge or salt absorbed the moisture in the air, the added weight was indicated on the graded disk, thus measuring the amount of humidity.

Leonardo’s researches for the altar painting took him almost a year. Although the monks began to grumble at his slowness, Leonardo would not be hurried. He was determined to produce a painting that was perfect in all respects. To quiet their impatience Leonardo did odd jobs for them in the cloister. He repainted their old clock and for this extra work they advanced him some much-needed money. In March of 1481 Leonardo was ready to begin the actual drawing for the altarpiece. As he progressed with the composition, the monks crowded around with exclamations of delight. So different was it from all the other Adoration pictures they had ever seen, that the monks sent Leonardo some sacks of corn as a token of their appreciation.

One day, Leonardo was walking slowly toward the monastery over the Ponte Vecchio—the Old Bridge—across the Arno River. He made his way slowly up the hill past the construction for the new Pitti Palace. The morning was hot and the farmers moving into the city with their heavily laden carts were short-tempered. Leonardo stood to one side as he watched a pair of oxen straining to haul a wagon up a rise in the road. Their owner, his shirt unbuttoned to the waist, was shouting angrily, lashing the animals with his leather-thonged whip. It was a cruel sight and Leonardo turned away. From some experiments he had been making, Leonardo realized that the poor animals were struggling not only with the hill, but the drag of friction on the creaking axle. This drag could be eased, he thought to himself, by simply resting the axle in two sets of roller-bearings attached to the bottom of the cart near each wheel. In his mind he formed the plan for such a model as he made his way to the monastery.

The drawing of the altarpiece was nearing completion. The monks were fascinated by the spectacle of the Adoration appearing before their eyes. The soft, umber outlines deepened with gray, the ochre highlighting the central figures charmed them and they sent another gift to Leonardo’s house—a cask of Tuscan red wine.