My father’s slide rule was a Keuffel & Esser log-log-duplex-decitrig slide rule from the 1940s, with twenty-one scales on white plastic bonded to teak and a glass hairline indicator, neatly cozied in a stiff leather case. Like all handymen and engineers of his generation, he took his slipstick seriously. Used it all day long, every day. While at work, while tinkering in his basement workshop, or while preparing a speech for the local chapter of the American Association of Mechanical Engineers. He lived in a world of three significant figures. 3.14 26.9 658 That was the best accuracy you could read off the scales. It was enough for a life of service to his profession and his community. With a slide rule, the structure of thinking is visible and tactile. He liked that. He could see and feel the numbers add, multiply, divide. Today, calculations take place invisibly in a microchip sealed away from human inspection.
With the transition from slide rule to electronic calculator—which happened just after his death— more happened than a mere advance in technology. The change from slide rules to electronic calculators was different, say, than the change from oil lamps to electric bulbs, or from horse-and-buggies to automobiles. The passing of the slide rule represented a change in how we understand the world. It was a change from analog to digital, from a world imagined as hardware to a world imagined as software. The dance of digits inside a computer’s silicon chip has not only transformed our lives; it has provided a new metaphor for understanding reality. The dance of the DNA in every cell of our bodies is more like the digital dance of 1s and 0s in a computer chip than it is like the cogs and gears of a clockwork. Today, it sometimes seems that nature is digital all the way down.
When I went off to college to study engineering in the 1950s, my father gave me his well-worn K&E slide rule. A thing of beauty. “Wear it with pride,” he might have said. And I did, as I trotted to class with the other engineering nerds, slip-sticks dangling from our belts. If someone had told us then that we would soon carry in the palm of our hand a device costing less than a good K&E slide rule that could do arithmetic and a host of higher mathematical functions instantly and accurately to ten significant figures we would have said, “Impossible.” But slide rules had one advantage over calculators: They rounded off, by necessity. They lent themselves to the kind of back-of-the-envelope calculations my father excelled at. He would have called it the art of rounding off, and of making reasonable guesses. Yes, an art. An art that may have passed away with that most lovely of mathematical devices—the slide rule. Too much precision can sometimes obscure understanding, I once heard him say. A lot of good science can be done with “let’s assume” and “to a first approximation.” (The slide rule is now in my son Tom’s possession, a treasured memento of his handyman grandfather.)
And while I’m lamenting the passing of the analog tools of my father’s generation, let me make a nod to another skill that floats through his deathbed journals in his sketches of his body on the bed. Mechanical drawing. It was one of the first courses I took as an engineering student at the University of Notre Dame in 1954.
What fun! To sit at a drafting table with the beautiful drawing instruments I inherited from my father and draw screw threads, bolt heads, and machine parts in isometric projection. Our textbook was Thomas Ewing French’s Mechanical Drawing, the very same book my father had used at the University of Tennessee a generation earlier. I still recall the lovely tactile feel of the precision compass with interchangeable tips for ink or lead, the three-sided rule, the sandpaper paddle on which to shape the pencil lead, the T-square, the clear plastic French curves. One of those curves was suited for the arcs of ellipses, another for parabolas, and another for hyperbolas. I always wondered if French curves were named after the author of our textbook, but no, it seems they were invented by the British designer Robin Ogilvie-Stewart Barrow and inspired by the shapes of croissants in the window of a Parisian bistro. They had a lovely Art Deco look that might equally have been inspired by Art Deco Paris. There was something sensual and deliberate about mechanical drawing. Nothing particularly creative. The emphasis was on technique and the consistent application of established conventions that the man in the machine shop who worked from the drawings could understand. Nevertheless, some students in the class had a special gift; their drawings were exquisite. Others students had a hard time drawing a straight line with their pencil point against a rule. I fell somewhere in between.
But I loved it, as I had loved as a boy the drawings my father made with the very same instruments. Some years ago, the art gallery at Stonehill College in Easton, Massachusetts, where I spent most of my professional life, featured a display of drawings from the industrial archive of the Ames Shovel Company, whose history is so intimately bound up with the history of the town and college. These precision drawings of machine parts were accompanied by semi-abstract interpretations by the artist Heather Hobler. It was lovely to see an artist of Hobler’s talent offer homage to the engineering draftsperson, an implicit recognition of the esthetic qualities of any drawing well-drawn, even that of a machine for shaping the blades of shovels.
All that’s gone now. The compass, the T-square, the French curves, the thin graphite lines on crisp white paper. Today, it’s all done with computers—CAD, computer-aided design. No doubt CAD vastly simplifies design, in the same way spreadsheets simplify the analysis of data. Every point in the plan for a six-inch widget or a ten-storey building is defined by a vector, a set of numbers buried deep inside a computer. A twist of the mouse and you can view the object from any angle. Change one vector and the program automatically makes all the necessary adjustments. A marvelous facility. There is no going back to the days of stainless-steel drawing tools. But something has been lost, something that defined the handyman philosophy of life. Something tactile, sensual, hold-in-the-hand. That line of India ink leaking off the carefully tensioned points of the compass or drawing pen. Something deliciously analogical. A pleasure such as one might get feeling raindrops on the face, or a lover’s touch. Sense and intellect in a merry dance of flesh.
I wonder if my copy of French’s Mechanical Drawing is still up in the attic, and I wonder what became of my father’s copy, which still floated around the family house in Chattanooga when I was growing up. I would love to thumb through either one again and relive in memory those pleasurable afternoon hours on the drafting table at the University of Notre Dame, and trace again the esthetic and technical roots of the poignant drawings of his twisted body that filled my father’s journals as he died.