About 500 years ago, Leonardo Da Vinci (1452-1519) recorded ideas about vortices based on his experiments with water. In fact, the subject of water, hydrology, and hydraulics made up a large part of Leonardo's lifetime study. As a matter of historic note - more of Da Vinci's writings were devoted to the subject of water than any other subject. The existence of water and its vortices intrigued Da Vinci, prompting him to speculate about the existence and behavior of vortices in the air and cosmos. The power and meaning of vortices in water also led him to closely study the behavior of water under different conditions.
Da Vinci's fascination with fluid dynamics and vortices crossed over into his art - with the flowing motions of water and vortices being expressed in his paintings and sculptures.
The existence and behavior of bubbles in water was also of interest to Da Vinci, since he noted from close observation that bubbles rise through water in a spiral motion. In his written notes in the Codex Leicester Folio 23V (now owned by Bill Gates), he observed that the "motions of waters always move in a circle from surface to bottom."
Da Vinci spent many years in his makeshift laboratory and in the field observing the movements of water and air. To see the fluid dynamics of water at work, he did experiments using glass tanks so he could watch the motion of flowing water under various scenarios. During his field research, he maintained detailed notes and drawings to record his experiences and observations.
To facilitate his research, he invented a water gate that utilized the pressure of water to create a tight seal. Unforseen by DaVinci at the time - his experiments and detailed technical drawings of this water gate would survive through time and eventually be used in designing the lock gate system of the Panama Canal.
At times, Da Vinci's mind would ponder the many realms of water as his observations often triggered writing ideas. As a habit, he would jot down or sketch these thoughts along the margins of his papers while working on other subjects. One such series of notes in the upper right hand corner of one of his papers provides us with his outline for a proposed treatise on water. It was divided into fifteen books, with each book dealing with a different aspect of water:
1. Of Water in Itself
2. Of the Sea
3. Of the Veins
4. Of Rivers
5. Of the Nature of Bottoms
6. Of Objects
7. Of Various Kinds of Gravel
8. Of the Surface of Water
9. Of Things Moving in It
10. Of River Repairs
11. Of Conduits
12. Of Canals
13. Of Machines Turned by Water
14. Of Raising Water
15. Of Things Worn Away by Water
Given the numerous other activities Leonardo was involved in, he never found the time to complete this series of water books. His writings, especially the Codex Leicester, contain many references and brief notes to be included in these books. An example of this can be found in his notes dealing with precipitation: "Write how clouds are formed and how they dissolve, and what it is that causes vapour to rise from the water of the earth into the air, and the cause of mists and of the air becoming thickened, and why it appears more blue or less blue at one time than another. Write in the same way of the regions of the air and the cause of snow and hail, and how water contracts and becomes hard in the form of ice, and of the new shapes that the snow forms in the air."
Another of Da Vinci's field observations explored the physical expression of the vortex principle on a grand scale. His written observations about a water spout he saw along the seashore were recorded on a page entitled "Of wind twists and eddies involving water." As expressed in Da Vinci's inimitable words:
It often happens that, when one wind meets another at an obtuse angle, these two winds circle around together and twine themselves into the shape of a huge column, and becoming thus condensed, the air acquires weight. I once saw such winds, raging around together, produce a hollow in the sand of the seashore as deep as the height of a man, removing from it stones of considerable size, and carrying sand and seaweed though the air for the space of a mile and dropping them in the water, whirling them around and transforming them into a dense column, which formed dark thick clouds as its upper extremity.
Many people will probably never see such a waterspout land on shore in their lifetime, but thanks to Da Vinci and his detailed notes from long ago, we have the opportunity to appreciate the feeling of such an experience.