The Moodus noises: Hosmer’s reports, the carbuncle legend and the measured earthquakes

Around Moodus in East Haddam, Connecticut, sudden reports, rumblings and shaking became the subject of religious explanation, folklore and scientific investigation. The historical record does not describe one isolated unexplained bang. It describes recurring disturbances, quiet intervals and occasional stronger shocks, interpreted differently by successive observers. Later measurements established unusually shallow local earthquake activity, while stories about subterranean beings and a stolen luminous gem continued to circulate.

The sources preserve several distinct kinds of evidence: a minister’s account dated 1729, a later resident’s description quoted by a historian, an early nineteenth-century traveller’s discussion, literary folklore and twentieth-century geophysical research. Keeping those layers apart matters. An old explanation is evidence that an explanation was recorded; it is not automatically evidence that its supernatural characters existed or that every sound had one demonstrable cause.

Hosmer’s letter: what he said he heard

Benjamin Trumbull’s History of Connecticut, volume II, printed pages 65–67, reproduces a letter from the Reverend Stephen Hosmer to Mr Prince of Boston dated 13 August 1729. The edition consulted here was published in 1898 and reprints an earlier history. The letter’s date belongs to Hosmer’s account, not to the date of that later edition.

Hosmer located the apparent centre of the disturbances within his own precinct. He said that they had been observed there for more than thirty years, while distinguishing that longer history from his own experience of hearing several hundred sounds over about twenty years. He described eight or ten small-arms-like reports within five minutes, sometimes frequent activity over a year, and sounds which seemed to approach from the north like slow thunder.

In his description, the approaching rumble could culminate in a break like cannon fire or heavy thunder, shaking houses and their contents. That is a witness’s description using familiar comparisons, rather than an instrumental measurement of speed, direction or depth. It is nevertheless more specific than a general assertion that people found the hill uncanny: sound, perceived approach and physical shaking were linked in his account.

Hosmer considered whether disturbed fire or air in underground cavities might be responsible, but said that the mechanism could not be known from what was visible. He reported no perceptible eruption, only sounds and tremors. He also said that activity had largely ceased after what he called the great earthquake, with only two moderate occurrences remembered afterwards. That reference should not be confused with the damaging Moodus earthquake of 1791, which lay decades in the future when the letter was written.

The limits of the religious explanation

The same letter carries Hosmer’s religious interpretation. It recounts information he had received about earlier Indigenous inhabitants and ceremonies, and attributes an explanation of divine anger to an unnamed Indigenous person. Hosmer’s own language describes Indigenous religion through a hostile Christian vocabulary. He did not present himself as the direct recorder of that person’s words in a documented interview.

This is therefore a colonial minister’s account of what he had been told, with his own assumptions attached. It cannot establish a single, verified Indigenous tradition about the sounds. Nor does his uncertainty about a physical mechanism establish a diabolical cause. His record is strongest where it specifies what he claimed to hear and feel; the source trail becomes less direct where it explains another community’s beliefs.

Familiar noises and a frightening night in 1791

Trumbull follows Hosmer with an unnamed long-term resident’s account. The resident compared the sounds with reports ranging from a pistol to a cannon, and the jolt to a house with heavy logs falling on its floor. Smaller occurrences had become familiar enough to cause little alarm. The distinction in local usage was that the usual small disturbances were called Moodus noises, while shocks felt in neighbouring towns were called earthquakes.

That account describes a much more frightening night in May 1791: two strong shocks, damaged chimneys and walls, followed by numerous lesser shocks. It reports displaced stones and openings in the ground discovered afterwards. These are historical reports of damage and its interpretation, not a modern survey establishing the origin of every crack. The observer said that disturbances became less frequent afterwards but did not disappear altogether.

There is a dating disagreement in the consulted sources. Trumbull’s quoted resident gives 18 May 1791, whereas the 1988 borehole report identifies the major event as 16 May. The distinction is retained here rather than silently replacing the historical wording. Likewise, the resident’s relative phrase about years of residence is part of Trumbull’s earlier compilation; it cannot be dated simply by counting backwards from the 1898 reprint.

Kendall’s early natural explanation

Edward Augustus Kendall’s Travels through the Northern Parts of the United States, published in 1809, discusses the noises on printed pages 99–103 of volume I. He quotes an American topographer’s account before qualifying its statement that the sounds were frequent. According to information he received, they had recently been rare. This is evidence of competing descriptions and changing reported frequency, rather than proof that every earlier report was mistaken.

Kendall associated the phenomenon with earthquakes and challenged the inference that Indigenous ceremonies produced the sounds. He suggested the reverse relationship: ceremonies were conducted because the sounds occurred. His discussion also explored ideas about underground combustion and changing natural conditions. Those speculative mechanisms belong to his period; they should not be presented as the findings of later seismological research.

The carbuncle story as folklore

The Moodus chapter in Charles M. Skinner’s Myths and Legends of Our Own Land offers a much more elaborate narrative. Witches contend in a subterranean chamber illuminated by a great carbuncle, a luminous gem. An English visitor called Doctor Steele prepares secretly to obtain it, opens the cavern and departs with the stone. In this version his ship sinks, while the gem’s red light can still be imagined shining upward through the sea.

That is a literary folklore account, with its own dramatic sequence. It is not a verified record of an English expedition, a recovered gemstone or a vessel lost through supernatural agency. Its reuse of Hosmer’s letter does not independently corroborate the letter’s observations. The later tale shows how a recurring sound could acquire characters, treasure and an explanation for its return.

What the instruments added

The published abstract of Ebel, Vudler and Celata’s 1982 study reports more than 500 events during August–October 1981. It describes thirty-nine foreshocks before a magnitude 2.1 mainshock, aftershocks and later smaller bursts. The events were within about one kilometre of the surface along a five-kilometre stretch of the Salmon River. Residents heard some events as small as magnitude zero and felt some below magnitude one.

Those findings provide a measured physical basis for small local disturbances being audible. They do not require a large destructive earthquake whenever someone hears a report. The accessible source used for those numerical findings is the researchers’ abstract; the full four-page paper was not read for this account. It is not a retrospective instrumental identification of each sound Hosmer heard.

The Moodus Borehole Research Project report, prepared by Woodward-Clyde Consultants in December 1988, describes a further investigation of local tectonic stress. Its programme combined drilling, geological and geophysical logging, and seismic monitoring. Drilling took place from 21 March to 12 June 1987, reaching approximately 1.5 kilometres. The project sought measurements near the depth range implicated in the local earthquakes, rather than a search for the cave or jewel of the legend.

Measured seismic events and historical stories answer different questions. Instrumental observations support a geological explanation for the documented modern activity. The older records show how people perceived and interpreted disturbances with much less information. They do not justify treating all present uncertainty about individual historical sounds as evidence for a supernatural source, or declaring that the contemporary experiments reproduced every eighteenth-century experience.

Sources, image and related reading

The historical account rests on Trumbull’s reproduced letter and resident’s account, checked against the original printed pages, and Kendall’s early discussion. Skinner is used as a source for a particular folklore narrative. The 1982 abstract supplies the swarm figures. Selected original pages of the 1988 report, including its seismic setting and drilling summary, were read visually; its full 510 pages were not exhaustively reviewed.

The photograph shows a modern landscape at Machimoodus State Park. It identifies the wider setting, not a particular epicentre, Hosmer’s house or the location of a documented supernatural event. Compare the Hanging Hills black dog for another Connecticut story whose literary source must be distinguished from later claims of witnessed events. No speculative underground feature or unverified map coordinate is supplied.

Map location — approximate area: The pin uses Moodus locality. It is a rounded locality reference, not an earthquake epicentre, underground cave or Hosmer’s house. Coordinate reference: U.S. Census Bureau 2025 Gazetteer representative area point. It gives no directions to private property.