Often, on late afternoons in midsummer, I have looked out to the half circle of hills to the west of Boston and its suburbs. As heat and humidity hang over the city, puffy cumulus clouds appear over the low hills, silently, inexorably expanding. What holds my attention is not just their rising forms, but the unseen turgid pillars of over-heated air from which the clouds build.
The clouds tell me that the uneven terrain of field, forest, roofs, and pavement is releasing warmth absorbed from the sun during the day, creating condensation where it encounters cooler air above.
Depending on the disparity in temperatures, fleecy cumulus may darken and expand into anvil-shaped cumulonimbus storm clouds. The son et lumiére of a summer shower may follow. The spectacle may be confined to the hills, or the downpour may reach the city, with sheets of rain veiling the vista.
My fascination with the panorama goes back to a high school science project for which I chose meteorology. I spent my weekends watching and identifying clouds - stratus, cirrus, nimbus, cumulus - with textbook in hand. I often observed them from the heights above my southern California town, where I had a view to the west over the Pacific and to the east over rolling hills to the coastal mountains. Since summer storms were rare along the coast, cumulonimbus remained a textbook phenomenon. Perhaps that's why I find them riveting when I do encounter them.
But it's not just summer storms that keep me at the windows. When spring zephyrs replace winter's blasts, birds and leaves aloft reveal invisible currents of air over trees and between buildings. Then I'm reminded of a series of photos in a science magazine in which whorls of colored dust in a wind tunnel were photographed. All this goes on now outside my windows, and the birds spread their wings to surf on these unseen waves.
One writer has likened them to shelves upon which the birds can rest during their flight. That writer was one of the giants of early navigation, meteorology, and natural science: Guy Murchie. It was Murchie's book, "Song of the Sky" - a lyric paean to the sky, the weather, and air flight by a World War II pilot turned commercial navigator - that propelled my interest in ethereal realms. The book is illustrated with his detailed etchings and woodcuts of aerial phenomena. My favorite is the giant swirl of a hurricane - composed of thousands of minute dots.
I have Murchie's book on my writing table now - although not the copy I read in high school. Just as the lore from that long-ago study brought me to the windows to observe the clouds, so the vistas of cloud and sky brought the book to memory and impelled a recent Internet search. That search also turned up Murchie's "The Music of the Spheres" - a later exploration of the chemistry and physics of the cosmos in relation to music. A university syllabus lists it for a workshop on - aesthetics!
Although subsequent space exploration has dated "Song of the Sky," it remains a sought-after classic. And no wonder. The inchoate knowledge of the early '50s unfolds as the spellbinding story within a story of a transatlantic cargo flight, with Murchie narrating from the cockpit against the hum of the instruments and the wail of the wind outside.
A musician in his spare time, Murchie, with his wife, later established a summer camp for young musicians in New Hampshire. Although today the Web shows a music camp by the same name in another town, several e-mails - sent in hopes of bringing Murchie's legacy full circle - have so far brought no confirming response.
The summer sky has grown dark outside my open window, and the air is warm, close, and heavy with moisture. Thunderstorms are predicted for tomorrow. And I, perhaps among the few, will welcome them.