In the summer of 1945, Robert J. Oppenheimer and other key members of the Manhattan Project gathered in New Mexico to witness the first atomic bomb test. Among the observers was Vannevar Bush, who had overseen the Manhattan Project and served as the sole liaison to U.S. President Franklin D. Roosevelt on progress toward the bomb.

Remarkably, given his intense wartime responsibilities, Bush continued to develop his own ideas about computing and information. Just days before the Trinity test, he had published in The Atlantic Monthly a futuristic account of networks of information knitted together via “associative trails”—which we would now call hypertext or hyperlinks. To this day, Bush’s article—titled “As We May Think”—and his subsequent elaborations of networked information appliances are credited with shaping what would become the personal computer and the World Wide Web. And during his lifetime, Bush was celebrated as one of the nation’s leading prophets of technological change and the most influential proponent of government funding of science and engineering.

Vannevar Bush’s influential 1945 essay “As We May Think” shaped the subsequent development of the personal computer and the World Wide Web. The Atlantic Monthly

And yet, if you watched this year’s Oscar-winning Oppenheimer, Bush is only a minor character. Played by actor Matthew Modine, he testifies before a secret government panel that will decide whether Oppenheimer, scientific director of the Manhattan Project, should be stripped of his security clearance and banished from participating in future government decisions on sensitive technological issues.

“Try me, if you want to try him,” Bush defiantly tells the panel. Alas, tragedy unfolds when the panel punishes Oppenheimer for his opposition to testing the nation’s first hydrogen bomb. No more is said about Bush, even though he also opposed the first H-bomb test, on the grounds that the test, held on 1 November 1952, would help the Soviet Union build its own superweapon and accelerate a nuclear arms race. Bush was spared sanction and continued to serve in government, while Oppenheimer became a pariah.

Today, though, Oppenheimer is lionized while Bush is little known outside a small circle of historians, computer scientists, and policy thinkers. And yet, Bush’s legacy is without a doubt the more significant one for engineers and scientists, entrepreneurs, and public policymakers. He died at the age of 84 on 28 June 1974, and the 50th anniversary of his death seems like a good time to reflect on all that Vannevar Bush did to harness technological innovation as the chief source of economic, political, and military power for the United States and other leading nations.

Vannevar Bush and the Funding of Science & Engineering

Beginning in 1940, and with the ear of the president and leading scientific and engineering organizations, Vannevar Bush promoted the importance of supporting all aspects of research, including in universities, the military, and industry. Bush’s vision was shaped by World War II and America’s need to rapidly mobilize scientists and engineers for war fighting and defense. And it deepened during the long Cold War.

Bush’s pivotal contribution was his creation of the “research contract,” whereby public funds are awarded to civilian scientists and engineers based on effort, not just outcomes (as had been normal before World War II). This freedom to try new things and take risks transformed relations between government, business, and academia. By the end of the war, Bush’s research organization was spending US $3 million a week (about $52 million in today’s dollars) on some 6,000 researchers, most of them university professors and corporate engineers.

On its 3 April 1944 cover, Time called Vannevar Bush the “General of Physics,” for his role in accelerating wartime R&D.Ernest Hamlin Baker/TIME

Celebrated as the “general of physics” on the cover of Time magazine in 1944, Bush served as the first research chief of the newly created Department of Defense in 1947. Three years later, he successfully advocated for the creation of a national science foundation, to nourish and sustain civilian R&D. In launching his campaign for the foundation, Bush issued a report, entitled Science, The Endless Frontier, in which he argued that the nation’s future prosperity and the American spirit of “frontier” exploration depended on advances in science and engineering.

Bush’s influence went well beyond the politics of research and the mobilization of technology for national security. He was also a business innovator. In the 1920s, he cofounded Raytheon, and the company competed with behemoth RCA in the design and manufacture of vacuum tubes. As a professor and later dean of engineering at the Massachusetts Institute of Technology, he crafted incentives for professors to consult part time for business, setting in motion in the 1920s and 1930s practices now considered essential to science-based industry.

Bush’s beliefs influenced Frederick Terman, a doctoral student of his, to join Stanford University, where Terman played a decisive role in the birth of Silicon Valley. Another Bush doctoral student, Claude Shannon, joined Bell Labs and founded information theory. As a friend and trusted adviser to Georges Doriot, Bush helped launch one of the first venture capital firms, American Research and Development Corp.

Vannevar Bush’s Contributions to Computing

Starting in the 1920s, Bush began designing analog computing machines, known as differential analyzers. This version was at Aberdeen Proving Ground, in Maryland.MIT Museum

But wait, there’s more! Bush was a major figure in the early history of modern computing. In the 1930s, he gained prestige as the designer of a room-size analog computing machine known as the “differential analyzer,” then considered the most powerful calculating machine on the planet. It was visually impressive enough that UCLA’s differential analyzer had a major cameo in the 1951 sci-fi movie When Worlds Collide.

In the 1940s, despite his busy schedule with the Manhattan Project, Bush set aside time to envision and build working models of a desktop “memory extender,” or memex, to assist professionals in managing information and making decisions. And, as mentioned, he published that pivotal Atlantic article.

For engineers, Bush carries a special significance because of his passionate arguments throughout his life that all engineers—especially electrical engineers—deserve the same professional status as doctors, lawyers, and judges. Before World War II, engineers were viewed chiefly as workers for hire who did what they were told by their employers, but Bush eloquently insisted that engineers possessed professional rights and obligations and that they delivered their expert judgments independently and, when feasible, with the public interest in mind.

Vannevar Bush considered engineering not just a job but a calling. John Lent/AP

From the distance of a half century, Bush’s record as a futurist was mixed. He failed to envision the enormous expansion of both digital processing power and storage. He loudly proclaimed that miniaturized analog images stored on microfilm would long provide ample storage. (To be fair, many old microfilm and microfiche archives remain readable, unlike, say, digital video disks and old floppies.)

And yet, Bush’s ideas about the future of information have proved prescient. He believed, for example, that human consciousness could be enhanced through computational aids and that the automation of routine cognitive tasks could liberate human minds to concentrate and solve more difficult problems.

In this regard, Bush prefigures later computing pioneers like Douglas Engelbart (inventor of the mouse) and Larry Page (cofounder of Google), who promoted the concept of human “augmentation” through innovative digital means, such as hypertext and search, and enhancing the speed, accuracy, and depth of purposeful thought. Indeed, today’s debate over the harm to humans from generative AI could benefit from Bush’s own calm assessment about the creative, intellectual, and artistic benefits to be gained from “the revolution in machines to reduce mental drudgery.” The subject of human enhancement through digital systems was “almost constantly” on his mind, he wrote in his 1970 memoir, Pieces of the Action, four years before his death. Bush cautioned against hysteria in the face of digitally mediated cognitive enhancements. And he insisted that our technological systems should maintain the proverbial “human in the loop,” in order to honor and safeguard our values in the tricky management of digital information systems.

The fate of human culture and values was not Bush’s only worry. In his later life, he fretted about the spread of nuclear weapons and the risk of their use. Fittingly, as the titular head of the Manhattan Project and, in the 1950s, an opponent of testing the first H-bomb, he saw nuclear weapons as an existential threat to all life on the planet.

Bush identified no ultimate solutions to these problems. Having done so much to enhance and solidify the role of scientists and engineers in the advancement of society, he nevertheless foresaw an uncertain world, where scientific and technological outcomes would also continue to challenge us.

In 1870, William Thomson, mourning the death of his wife and flush with cash from various patents related to the laying of the first transatlantic telegraph cable, decided to buy a yacht. His schooner, the Lalla Rookh, became Thomson’s summer home and his base for hosting scientific parties. It also gave him firsthand experience with the challenge of accurately predicting tides.

Mariners have always been mindful of the tides lest they find themselves beached on low-lying shoals. Naval admirals guarded tide charts as top-secret information. Civilizations recognized a relationship between the tides and the moon early on, but it wasn’t until 1687 that Isaac Newton explained how the gravitational forces of the sun and the moon caused them. Nine decades later, the French astronomer and mathematician Pierre-Simon Laplace suggested that the tides could be represented as harmonic oscillations. And a century after that, Thomson used that concept to design the first machine for predicting them.

Lord Kelvin’s Rising Tide

William Thomson was born on 26 June 1824, which means this month marks his 200th birthday and a perfect time to reflect on his all-around genius. Thomson was a mathematician, physicist, engineer, and professor of natural philosophy. Queen Victoria knighted him in 1866 for his work on the transatlantic cable, then elevated him to the rank of baron in 1892 for his contributions to thermodynamics, and so he is often remembered as Lord Kelvin. He determined the correct value of absolute zero, for which he is honored by the SI unit of temperature—the kelvin. He dabbled in atmospheric electricity, was a proponent of the vortex theory of the atom, and in the absence of any knowledge of radioactivity made a rather poor estimation of the age of the Earth, which he gave as somewhere between 24 million and 400 million years.

William Thomson, also known as Lord Kelvin, is best known for establishing the value of absolute zero. He believed in the practical application of scientific knowledge and invented a wide array of useful, and beautiful, devices. Pictorial Press/Alamy

Thomson’s tide-predicting machine calculated the tide pattern for a given location based on 10 cyclic constituents associated with the periodic motions of the Earth, sun, and moon. (There are actually hundreds of periodic motions associated with these objects, but modern tidal analysis uses only the 37 of them that have the most significant effects.) The most notable one is the lunar semidiurnal, observable in areas that have two high tides and two low tides each day, due to the effects of the moon. The period of a lunar semidiurnal is 12 hours and 25 minutes—half of a lunar day, which lasts 24 hours and 50 minutes.

As Laplace had suggested in 1775, each tidal constituent can be represented as a repeating cosine curve, but those curves are specific to a location and can be calculated only through the collection of tidal data. Luckily for Thomson, many ports had been logging tides for decades. For places that did not have complete logs, Thomson designed both an improved tide gauge and a tidal harmonic analyzer.

On Thomson’s tide-predicting machine, each of 10 components was associated with a specific tidal constituent and had its own gearing to set the amplitude. The components were geared together so that their periods were proportional to the periods of the tidal constituents. A single crank turned all of the gears simultaneously, having the effect of summing each of the cosine curves. As the user turned the crank, an ink pen traced the resulting complex curve on a moving roll of paper. The device marked each hour with a small horizontal mark, making a deeper notch each day at noon. Turning the wheel rapidly allowed the user to run a year’s worth of tide readings in about 4 hours.

Although Thomson is credited with designing the machine, in his paper “The Tide Gauge, Tidal Harmonic Analyser, and Tide Predicter” (published in Minutes of the Proceedings of the Institution of Civil Engineers), he acknowledges a number of people who helped him solve specific problems. Craftsman Alexander Légé drew up the plan for the screw gearing for the motions of the shafts and constructed the initial prototype machine and subsequent models. Edward Roberts of the Nautical Almanac Office completed the arithmetic to express the ratio of shaft speeds. Thomson’s older brother, James, a professor of civil engineering at Queen’s College Belfast, designed the disk-globe-and-cylinder integrator that was used for the tidal harmonic analyzer. Thomson’s generous acknowledgments are a reminder that the work of engineers is almost always a team effort.

Like Thomson’s tide-prediction machine, these two devices, developed at the U.S. Coast and Geodetic Survey, also looked at tidal harmonic oscillations. William Ferrel’s machine [left] used 19 tidal constituents, while the later machine by Rollin A. Harris and E.G. Fischer [right], relied on 37 constituents. U.S. Coast and Geodetic Survey/NOAA

As with many inventions, the tide predictor was simultaneously and independently developed elsewhere and continued to be improved by others, as did the science of tide prediction. In 1874 in the United States, William Ferrel, a mathematician with the Coast and Geodetic Survey, developed a similar harmonic analysis and prediction device that used 19 harmonic constituents. George Darwin, second son of the famous naturalist, modified and improved the harmonic analysis and published several articles on tides throughout the 1880s. Oceanographer Rollin A. Harris wrote several editions of the Manual of Tides for the Coast and Geodetic Survey from 1897 to 1907, and in 1910 he developed, with E.G. Fischer, a tide-predicting machine that used 37 constituents. In the 1920s, Arthur Doodson of the Tidal Institute of the University of Liverpool, in England, and Paul Schureman of the Coast and Geodetic Survey further refined techniques for harmonic analysis and prediction that served for decades. Because of the complexity of the math involved, many of these old brass machines remained in use into the 1950s, when electronic computers finally took over the work of predicting tides.

What Else Did Lord Kelvin Invent?

As regular readers of this column know, I always feature a museum object from the history of computer or electrical engineering and then spin out a story. When I started scouring museum collections for a suitable artifact for Thomson, I was almost paralyzed by the plethora of choices.

I considered Thomson’s double-curb transmitter, which was designed for use with the 1858 transatlantic cable to speed up telegraph signals. Thomson had sailed on the HMS Agamemnon in 1857 on its failed mission to lay a transatlantic cable and was instrumental to the team that finally succeeded.

Thomson invented the double-curb transmitter to speed up signals in transatlantic cables.Science Museum Group

I also thought about featuring one of his quadrant electrometers, which measured electrical charge. Indeed, Thomson introduced a number of instruments for measuring electricity, and a good part of his legacy is his work on the precise specifications of electrical units.

But I chose to highlight Thomson’s tide-predicting machine for a number of reasons: Thomson had a lifelong love of seafaring and made many contributions to marine technology that are sometimes overshadowed by his other work. And the tide-predicting machine is an example of an early analog computer that was much more useful than Babbage’s difference engine but not nearly as well known. Also, it is simply a beautiful machine. In fact, Thomson seems to have had a knack for designing stunningly gorgeous devices. (The tide-predicting machine at top and many other Kelvin inventions are in the collection of the Science Museum, in London.)

Thomson devised the quadrant electrometer to measure electric charge. Science Museum Group

The tide-predicting machine was not Thomson’s only contribution to maritime technology. He also patented a compass, an astronomical clock, a sounding machine, and a binnacle (a pedestal that houses nautical instruments). With respect to maritime science, Thomson thought and wrote much about the nature of waves. He mathematically explained the v-shaped wake patterns that ships and waterfowl make as they move across a body of water, which is aptly named the Kelvin wake pattern. He also described what is now known as a Kelvin wave, a type of wave that retains its shape as it moves along the shore due to the balancing of the Earth’s spin against a topographic boundary, such as a coastline.

Considering how much Thomson contributed to all things seafaring, it is amazing that these are some of his lesser known achievements. I guess if you have an insatiable curiosity, a robust grasp of mathematics and physics, and a strong desire to tinker with machinery and apply your scientific knowledge to solving practical problems that benefit humankind, you too have the means to come to great conclusions about the natural world. It can’t hurt to have a nice yacht to spend your summers on.

Part of a continuing series looking at historical artifacts that embrace the boundless potential of technology.

An abridged version of this article appears in the June 2024 print issue as “Brass for Brains.”

References

Before the days of online databases for their collections, museums would periodically publish catalogs of their collections. In 1877, the South Kensington Museum (originator of the collections of the Science Museum, in London, and now known as the Victoria & Albert Museum) published the third edition of its Catalogue of the Special Loan Collection of Scientific Apparatus, which lists a description of Lord Kelvin’s tide-predicting machine on page 11. That description is much more detailed, albeit more confusing, than its current online one.

In 1881, William Thomson published “The Tide Gauge, Tidal Harmonic Analyser, and Tide Predicter” in the Minutes of the Proceedings of the Institute of Civil Engineers, where he gave detailed information on each of those three devices.