My Grandfather's Level

Gouache and watercolor, JD, 2025

This much-used object, not so much antique as just worn from age, probably belonged to my paternal grandfather. He worked as a contractor coordinating construction products through the middle of the last century. Hammers, hand drills, saws, and other instruments of his trade were the main legacy he left to my father. Never a successful business man, he still managed to provide for his wife and family, since they had a row house in West Philadelphia and a car, though they struggled like everyone in the Depression. The tools are long gone now, sadly, misplaced or discarded in a downsizing move though they would have served well as a museum display of the hand technology of another era. The collection, “a worker’s tools,” would have been recognizable to many of an earlier generation. Now they might seem as remote as Neolithic axes to young viewers.

The physicality of this tool fascinates me, not just the way it carries history in the nicks and marks on its surface, and chipped edges, but in the basics of its conceptual design. This is a “bubble level” whose distinctive characteristic is the air bubble floating in the transparent tubes of vividly colored liquid (for which it is sometimes referred to as a “spirit level”). Vertical, horizontal, and parallel—the tubes offer three systems of calibration that can be calibrated with each other to determine whether an object, line, plank of wood or other entity is in true position. But relative to what? The question of the external reference frame raises all sorts of interesting questions—after all, the surface of the earth is curved, its forces unevenly distributed, and only at a certain small scale can we imagine that a horizontal line describes the level condition of a liquid suspended in a tube. Think about it….

Water, we know, “levels out” in a container. The effect of gravity assures this, but here is the curious paradox. For water to be “level” in a basin of any kind, each point on the surface must be the same distance from the center of the globe whose radius is drawn to that point. So, the illusion of the horizontal is a question of scale, with a larger perspective, the curvature of the earth would be evident as would the shape of the surface—a perception available on the open seas or at the beach where the horizon dips to either side even if ever so slightly.

Still, the idea of a spirit level, its air bubble suspended in tinted alcohol, must have been suggested by the movement of liquid in bowls and cups. Any builder would register the deviation from true against the edge of the container placed on a structure. The bubble level doesn’t so much measure as register information in analogue form. Alignment, rather than degrees of difference, are its forte. More precise levelling instruments provide the angle essential for correcting a skew beyond the simple fact of getting something straight, in that case, measuring the degree of deviation from 90 degrees or 270 degrees.

The level participates in the larger field known as metrology, the science of measure, which, you will be happy to know, had its “modern” boost in the French Revolution when, according to the Wiki, the metric system was invented as a new standard. Invented, yes, to replace the varied systems of measure used locally. The establishment of an international organization to oversee these standards took another century and even now, local conventions persist.

Human ingenuity is incredibly agile with respect to creating metrics. But imagine the tasks of standardizing units for measuring property, volume, and weight in advance of regulatory instruments. The parts of the body were used to create a reference for early measurements of length, height, and width. The observation of the heavens led to standards for timekeeping across cultures able to calculate the length of years, days, and lunar cycles. These temporal metrics, are, however, all earth-bound, determined from the point of view of the movement of our rocky planet in rotation and around the sun. A day on Venus and a year on Jupiter are vastly different from our own, and the concept of a “minute” as a subdivision of time, so apparently evident a subset of the divisions of days into hours, has no identity within the natural world outside of our conventions of degrees and clock-face elements. The cultural history of time and temporal systems is a study unto itself, fascinating for its variability and range. Atomic clocks provide a metric based on electromagnetic radiation and the frequency of atomic vibrations. This can then be used to regulate clock time. But what unit of measure is the atom producing for this translation? Are we back to seconds?

But the level belongs to the world of spatial measure, not temporal, and it assumes its authority by performing a straightforward physical act—though of course, nothing is that simple and even the relatively small space that separates the three tubes on my grandfather’s tool are technically in different coordinate spots on the surface of the globe to which they refer. The circumference of the earth comes close to 25,000 miles and the distance of a few inches is so minute a percentage that the difference in location is imperceptible to the human eye. But not to the human mind. So each time I set the level on a spot I think about that minute increment of difference, daring the bubbles in the liquid to defy their independent fate and behave as if they are in one single space–or vice versa, embrace their differences and flaunt them.

The history of measures stretches into antiquity, with the Egyptian cubit one apocryphal beginning. Created from the dimensions of the pharoah’s arm and hand and carved into black basalt, it supposedly served as a common reference. But that arms and hands, thumbs and fingers, were the basis of spatial units as well as of course, the digits of counting systems, makes good sense in some way–but troubles the problem of standards. For measures to be integrated into cultural life, they needed to be reified somehow, embodied in external objects that maintained their length and number no matter whose arms were used to generate the unit or whose thumbs were on the scales.

Read through the history of metrology and you are quickly enmeshed in a web of business transactions of all kinds—exchange of goods and trade values, units of storage and length. The need arose in the ancient Near East, where administrative tasks for managing property and goods emerged with the creation of surplus, particularly in relation to hard grains and other stuffs in their stored (seeds), pressed (oil), and fermented forms (beer). The “carat” used to gauge diamonds and other gems is traced to the carob seed as a unit of measure. How equitable the vegetable kingdom was with regard to the maintenance of standards is another issue. Some kernels are bigger than others. But grains of wheat and barley (again, thanks to the Wiki for this information) were used for gauging the weight of metals. Coinage puts these standards into circulation, and the bad habit of “nicking”—removing a fingernail’s worth of metal from a coin—was severely punished into modern times for the damage it did to stable values, a remarkable demonstration of the ways social order regulates itself. No one wants to be given a short measure of anything.

This is an inexhaustible topic, and the whole application of decimal systems, originally developed in Indian mathematics for ease of calculation, to systems of measure belongs to a chapter in the emergence of rational modernity in the 17th and 18^th centuries. We in the United States, of course, where our inches, feet, and yards preserve our connection to an earlier time (to the Romans and other ancients by way of the Britons and Celts) and have long resisted the adoption of the metric system. But the ways in which scientists and philosophers conceived of the problem from a systemic (relations of units to each other in a logical way) rather than referential (what can be used as a standard) perspective provides insight into the shift from earlier ways of thinking in terms of physical analogy into mathematical abstraction. What remains remarkable to me is that the ancients were able to compute the diameter of the earth, estimate its circumference, create, as Ptolemy did, a coordinate system for the globe and use it for mapping vast areas that could never have been viewed only experienced on the ground and from the water. That capacity to extrapolate from experience into systematic knowledge, however flawed, is inspirational.

And so this humble level, its bubble trapped in spirit (or vice versa), remains a testimonial to activities in which the hand and eye coordinated their capacities to assure that a table, shelf, or picture sat straight in relation to the position of the observer. What purpose the two deep dimples in its surface served is unclear, perhaps to secure the grip, or extend a visible line along their centers. Not quite a thing of beauty, but an object with thick associations still resonating on its surface. The signs of wear echo of the grip of other hands. My grandfather held this, and so did my father, and when I touch it I touch them, indirectly, but palpably, through the memory of their attempts, however tentative or transient, to establish equilibrium.