THE PREACHER VS THE VOLCANOLOGIST - ORIGIN OF THE WORD "PYRODUCT"

Titus Coan (1801-1882) was an influential Congregational missionary who made major contributions to the establishment of Christianity in Hawaii. He was also a gifted geological observer and was fascinated by the volcanic activity he witnessed after his 1835 arrival in Hawaii.

James D. Dana (1813-1895), who had already made major contributions to mineralogy, was appointed at age 25 to be the Geologist on the US Exploring Expedition (“Wilkes Expedition” – 1838-1842). He visited Hawaii for a month in 1840, where he met Coan. Dana later became Chairman of the Geology Department at Yale University and Editor of the influential Silliman Journal – forerunner to the American Journal of Science. He has been rightfully called “America’s First Volcanologist”. Coan’s letters to Dana about Hawaiian volcanic activity, published in the AJS, are the principal records of Hawaiian volcanic activity between 1840 and 1880.

His detailed observations of the 1843 Mauna Loa eruption are the earliest field descriptions of any eruption of that great volcano. After an arduous four day journey through dense forest above Hilo, he came to the advancing lava flow, and on the fifth day hiked up to the source vents high on Mauna Loa’s Northeast Rift Zone. Along the way, he witnessed openings into fiery subterranean “rivers of fire” that were supplying molten lava to flow fronts far below. He correctly noted the heat-insulating properties of these shallow underground tunnels, compared them to aqueducts, and wrote: “If I might be allowed to coin a word, this pyroduct – filled with mineral fusion, and flowing under our feet at the rate of twenty miles an hour, was truly startling”.

Coan’s pyroduct description was published in 1844 in an obscure journal, and re-published by Dana in 1850. In 1852, however, he rebutted Coan’s conclusions and declared that what Coan had witnessed were actually the tops of deep fissures that were cutting the flanks of Mauna Loa “a linear fissure or series of fissures, and not a single tunnel-like opening”. Dana continued to deny the existence of pyroducts in his publications, but, the preacher was right – and the professor wrong. Good field observations trump office speculations every time!