A Course of Mechanical, Magnetical, Optical, Hydrostatical and Pneumatical Experiments: perform'd by Francis Hauksbee, and the Explanatory Lectures read by William Whiston, M.A

In Short

This book is a comprehensive manual of physical science as understood in early eighteenth-century London. It serves as a pedagogical companion to a series of lectures, detailing experiments in mechanics, magnetism, optics, hydrostatics, and pneumatics. By documenting the exact apparatus and procedures used to demonstrate laws of motion, pressure, and light, the text provides a vivid snapshot of the era's scientific rigor. It has lasted as a primary source for historians of science, offering an intimate look at how foundational physical principles were first verified through tangible, mechanical observation.

The Story

The narrative arc of the volume follows the structured progression of a natural philosophy course. It begins with the fundamental laws of motion—the foundation of all subsequent inquiry—and moves systematically through the mechanical properties of solids, fluids, and gases. The opening sections establish the laws of falling bodies and the behavior of simple machines: levers, pulleys, wedges, and screws. Through these, the reader is guided toward a sophisticated understanding of how forces are resolved, balanced, and amplified, moving from basic experiments with weights to the complex interactions of compound engines.

Once the mechanics of solids are established, the focus shifts to the behavior of fluids. The text explores the pressures within liquids, the nature of specific gravity, and the Archimedean principles of buoyancy. It demystifies the "abhorrence of a vacuum," which formerly served as a placeholder explanation for atmospheric phenomena, replacing it with measurable evidence of air pressure and fluid displacement. This leads naturally to the study of pneumatics, where the air-pump and the Torricellian tube become the primary protagonists.

The progression continues into optics, where light is treated as a physical subject for manipulation. The text explains the behavior of light through reflection, refraction, and the dispersion of colors—moving from the basic geometry of mirrors to the more advanced study of prisms and lenses. The "Experimentum Crucis" serves as a pivotal demonstration, reinforcing the theory of light’s composition through a definitive, controlled process.

The volume concludes not with a grand philosophical synthesis, but with a return to the practical, gritty reality of the instruments themselves. The final sections detail the construction and operation of barometers, thermometers, and refined air-pumps. By the end, the reader has moved from the abstract laws of motion to the sophisticated calibration of instruments designed to measure the invisible weight of the atmosphere. The trajectory is one of increasing complexity, stripping away mystical explanations in favor of measurable, repeatable physical phenomena. It is an argument built on demonstration: every claim regarding the nature of the world is grounded in a specific, observable interaction between a machine and the physical environment. The book finishes by confirming that these instruments are available for purchase, anchoring the lofty goals of science directly to the commercial expertise of the instrument maker.

How It Unfolds

The Laws of Motion The text opens with the demonstration of Newtonian principles, using falling bodies and inclined planes to establish the relationship between time, velocity, and force. These initial experiments provide the logical framework for all later investigations into machines.

Mechanical Advantage Moving from theory to practice, the narrative explores the lever, the pulley, and the screw, showing how simple machines manipulate force. Each section provides a clear explanation of how weights can be balanced and motion translated.

The Physics of Fluids The focus transitions to hydrostatics, where the book demonstrates that fluids exert pressure in all directions. It explains the behavior of floating bodies and provides tables of specific gravity for a wide range of materials.

Atmospheric Inquiry In the study of pneumatics, the book demystifies the vacuum and the spring of the air. It utilizes barometers and air-pumps to measure the atmosphere’s pressure, effectively replacing older theories with a mechanical understanding of air.

The Nature of Light The final major section treats optics, detailing how lenses and prisms redirect light. It culminates in experiments that break white light into colors, proving the physical reality of the spectrum.

The People

The book is driven by the collaboration between the lecturer William Whiston and the instrument maker Francis Hauksbee. Whiston acts as the intellectual guide, tasked with translating complex natural laws into clear, explanatory lectures. His role is to ensure the reader understands the "why" behind the physical phenomena—he is the voice of logic and mathematical rigor, seeking to ground the reader in the established laws of nature.

Francis Hauksbee is the practical architect of this knowledge. His presence is felt in the precise description of the apparatus—the "strong hollow Cylindrical Barrels," the "Swan-neck'd" pipes, and the "newly contriv'd Stiliard." He represents the marriage of craftsmanship and science. While Whiston provides the explanation, Hauksbee provides the proof; he is the one who ensures the glass is ground true and the air-pump seal is tight enough to create a vacuum. Neither man is a traditional character in a narrative sense; rather, they represent the two sides of enlightenment-era science—the mathematician and the artisan. They do not change internally, but through their combined efforts, they transform the reader's view of the world from one of mystery to one of mechanical clarity.

In Its Own Voice

"That the Velocity of Falling Bodies is as the Times of Falling, and the Lines of Descent in the Duplicate Proportion of those Times."

This opening statement defines the foundational law of motion that governs the initial mechanical experiments.

"And this because the Velocity downward is ever to the Velocity side-ways in the Proportion of D B to D F and D E, or to 2 D F."

This geometric explanation details the precise force exerted by a wedge during a demonstration of its mechanical advantage.

"And here it is most remarkable, that the two Holes and second Prism are kept immoveable; and so the Rays G g fall upon the second Prism in the very same Angle, whatever Colour they are of."

This describes the Experimentum Crucis, a definitive test used to prove that the colors of the spectrum are immutable.

What It's Really About

At its core, this work is about the triumph of measurement over speculation. It argues that the universe is a machine, governed by consistent, mathematical laws that can be exposed through deliberate, controlled intervention. The central question is not merely how the world works, but how we can know that it works that way. By replacing the "nature's abhorrence of a vacuum" with the "spring and weight of the air," the text advocates for a scientific method where observation and instrumentation precede theory. It is a defense of the empirical, asserting that physical reality is composed of properties—like specific gravity, elasticity, and refraction—that are fundamentally measurable and, therefore, understandable by human reason.

Why Read It Today

Readers with a fascination for the history of technology or the philosophy of science will find this volume deeply rewarding. It offers a rare, ground-level view of how experimental physics was communicated in the eighteenth century, free from the layers of modern abstraction that often obscure the mechanical origins of our knowledge. The prose is clean, direct, and entirely focused on the mechanics of the experiments, making it a surprisingly tactile read; one can almost hear the ticking of the clocks, the rushing of the air through the stopcocks, and the grinding of the glass.

However, the modern reader should be prepared for a certain level of technical density. The text is not a light narrative; it is a transcript of rigorous inquiry. You will encounter archaic spellings—"Axel" for axle, "crouded" for crowded—and a period-specific focus on outdated concepts like the nature of "effluvia," which can be challenging to parse without a patient eye. Nevertheless, what stays with you is the sheer wonder of the era’s "new science." There is a profound, quiet thrill in reading about the first times humanity successfully measured the invisible weight of the atmosphere or separated light into its constituent colors. It serves as a reminder that the world we take for granted was once a set of mysteries that required the invention of the machine to be solved.