US Patent No. 122,075: What an improved butter churn reveals about A.T. Still, DO

A.T. Still, DO, had a habit of looking for a better way. Usually, his concern was finding a better way to treat injury and illness, but his interests went beyond improving the practice of medicine.

He grew impatient with squandering his precious time, skill and energy on mundane chores. Always fascinated with machinery and engineering, he shared his mother’s knack for fixing things and, since childhood, was a tinkerer. As an adult, this casual interest grew into something more serious.

As our profession recognizes Dr. Still’s birthday on Aug. 6, below is an exploration of what a patent for an improved butter churn tells us about the founder of osteopathic medicine.

Dr. Still undertook the formal study of machines, including milling, for some two years. He soon designed a better device “to collect and bundle the falling grain,” which he demonstrated to visitors from the Wood Mowing Machine Company. Before Dr. Still knew it, Wood added his device to their manufactured machines the following year. However, Dr. Still was not compensated for the use of his device, and that taught him a valuable lesson about the importance of patents. He was determined not to be cheated again.

Rethinking the butter churn

The churning of whole milk into butter was a laborious task using the familiar, even iconic, upright plunger-type churn universally found in dairy barns and farmhouses. Like much of the hard and tedious work of the nineteenth century, churning was often left to the “womenfolk,” but Dr. Still preferred to spare his wife this time-consuming labor. He pondered ways to reduce the energy and time expended in churning with the old-style dashers, as the plunger assembly was called.

Barrel churns, which replaced the up-and-down plunger with a hand-cranked dasher, offered some improvement. They were mostly variations on a design by the German master brewer Antonin Prandtl, who used centrifugal dasher paddles to achieve more efficient separation. But this was at most only an incremental improvement in churning, and Dr. Still believed that there must be a better way.

He made new dasher parts and changed the angle of the dashers, offsetting their attachment to the arms and increasing the revolutions hand-cranking produced to 800 per minute. This improved the efficiency of the churn, saving both time and energy.

Science behind the science

Though the spirit of the tinkerer never left Dr. Still, his innovation of the butter churn was not a product of mere intuition or trial and error. His invention demonstrated a comprehensive grasp of the science of butter-making, including the roles of centrifugal force, temperature, agitation and separation. These insights, in turn, grew from his understanding of the chemistry of milk and the knowledge that the key to the transformation of whole milk into butter was breaking the shell of the casein to convert the milk into valuable forms of cream and butter.

He also studied and determined the quantity of continuous agitation required to create the necessary collisions between the liberated fat globules. These collisions, along with exposure to air—for churning is also aeration—hastened the separation of butterfat from the milk. This, in turn, allowed for the solidification of butter, with the cream rising to the top.

Getting the patent

As he did in exploring and treating the human body, Dr. Still went beyond conventional practice and superficial understanding to find root causes and essential relationships. Tradition and hit-or-miss incremental improvements were insufficient. On Dec. 19, 1871, he was granted U.S. Patent number 122,075 for improvements in the butter churn-dasher. After creating this thoroughly innovated device and getting it patented, he set about marketing the churn for the next few years. He even took home a prize for his invention from the Douglas County Fair in September 1871.

Dr. Still’s better butter churn came seven years after Prandtl’s first iteration of his centrifugal churn but preceded by seven years Prandtl’s next iteration, a continuous cream separator, which debuted in 1877, rendering Dr. Still’s design obsolete.

Precision engineering

The specifications of Dr. Still’s churn, as well as the level of detail in the patent application, provide insight into his scientific inventiveness. As he wrote in the patent application, “My invention has for its object to furnish an improved dasher, which shall be so constructed as to bring the butter in a very short time, and with a comparatively small amount of labor, and which will keep the milk thoroughly mixed with air while being churned; and it consists in the construction and combination of the various parts of the dasher, as hereinafter more fully described.”

The dashers of the Still churn could be detached and adjusted on a radial arm to remain below the surface of the milk at an incline, so that, as the arm revolved, the milk would be subjected to centrifugal forces by projecting the liquid up and out, creating a “violent agitation, thoroughly mixing it with the air, and bringing the butter in a very short time.”

This description demonstrates Dr. Still’s knowledge and practical understanding of the physics behind the milk-to-butter molecular changes created by applying forces just beneath the top layer of milk, where critical exposure to the air occurs, and applying mechanical engineering that created a new dasher with paddles at precisely the angle that would produce the necessary centrifugal forces while consuming less energy and time. Whether in mechanics or the human body, Dr. Still appreciated, respected and marveled at efficiency.

From machine to human mechanics

While marketing his new butter churn, Dr. Still wrote, “All this study of human mechanics awoke with new vigor within me.” On June 22, 1874, at 10 a.m., he was shot “not in the heart but in the dome of reason” with the bullet-like epiphany that God’s work is perfect. It was on this day that Dr. Still famously “flung to the breeze the banner of osteopathy,” as he notes on pages 94-95 of his autobiography.

Having employed manipulative musculoskeletal methods early in his career, even before the Civil War, Dr. Still planned to further his study of these treatments by starting a new method of practicing medicine. His belief was that God had created humankind as a perfect biological machine that called for a mechanical approach to treatment.

“The Great Creator equipped man with the native forces sufficient to run the machinery of life safely and smoothly to a ripe old age, and he has wisely placed the means for applying and controlling them within easy reach,” he wrote in the Journal of Osteopathy.

The human body’s natural capacity for self-healing, Dr. Still realized, could often be hastened by perfecting the human machine and not poisoning it with mercury, whiskey and opium, the mainstays of the era’s pharmacopeia.

After inventing a better butter churn, Dr. Still vowed that he would perfect the means of healing the human body by “manual” neuromuscular mechanical methods whenever possible. Nearly two decades later, his crusade took a giant step forward with the opening of the American School of Osteopathy in 1892.

Additional reading:

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