The following is my translation of an article called: Rätselhafte Knallgeräusche von Friedrich Regensberg. It appeared in a German popular science magazine, Kosmos Handweiser für Naturfreunde 1909, Heft 1, Seiten 19-21. I'm not aware of any previous translation.
Trevor Dykes.

Puzzling bangs by Friedrich Regensberg
Strange noises and sounds have played a large role in the fantasies of people since the earliest times. (For comparison see the interesting article by Prof. Dr. Rosenfeld in Edition 4, Volume 5 about ringing stones): strange sounding tones, whistles and shot-like bangs were often perceived in contrasting areas of the natural world and, as there was no obvious explanation available for these occurrences, they presumably built the basis for various legendary figures (eg. the wild hunter). Especially remarkable, due to their commonness and their presence in different parts of the world, are banging sounds in the air.

The so called Seeschießen ('lake shooting') of Lake Constance counts among these puzzling phenomena and, as has been shown by a number of newspaper reports from recent years, this occurrence is certainly not restricted to the 'Swabian sea'. The same phenomenon of sound has been reported in Switzerland, Belgium, Sweden (Lake Wetten), from English and Scottish lakes, from Italy, India and so on, although known under different names. In Switzerland one calls it Wetterschießen ('weather shooting'); it has been detected between the Alps and Jura Mountains, but also on the north side of the Jura Mountains in the area of Alsace. It occurs as a dull, cannon-like bang especially on quiet, warm days when a light mist begins to draw across the sky. Rain usually closely follows, but this certainly has no connection with storms. Around the Swiss Jura lakes one speaks of Murtenschießen ('Murten shooting'), in the canton of Aargau Rothenburger Schießen; in Austria of Seebrüllen ('lake roaring'). Belgium, northern France, the Channel and possibly the entire North Sea up to Iceland have so called mist-puffers or rots (or hoquets) de mer, vague, dull noises but as different from shots as they are from thunder or it is from detonations. They are mostly heard in the summer on hot days (most often between noon and three pm), and the coastguard and seafarers interpret them as omens of fine weather. The Belgian academic, Dr van den Broeck, recently investigated these mist-puffers and he has published his observations. On the coast of Belgium, these noises are always reported as coming from far off in the westerly direction; fishermen maintain the sound comes from the depths of the sea. Detonations, which are also known in the Baltic Sea on a line between Kiel and Korför, sound in a number of reports one after another (2, 3, 5-20) at intervals of 30 seconds. The sky remains clear and a low mist covers only the motionless sea: mist-puffers. As a more careful observer realises, these noises are not detected solely by the hearing nerves but also by the nerve system as a whole. The sound seems like a buzz to the ear as when a drop of water remains in it after a bath. The noise is certainly connected with vibrations perceived by tremors as well as hearing. "The humming, which one often notices from steam kettles, has a similar effect as mist-puffers -a sensation that many people can share." The same occurrence was experienced by Dr van den Broeck and another witness on 6th April, 1896 in Middelkerke and Ostende. Various explanations have already been offered: earth movements, submarine acoustic waves, odd tensions between the air and sea, effects of the Sun, steam and so on.

In Italy, Milan has the so called Runtbi whereas elsewhere, because of similarties with thunder, it is termed Brontidi. Prof. Alippi, the director of the meteorological and seismic observatory in Urbino, has undertaken research into this particular concern, and has published a special study on it. The sounds are mostly dull but also stretched like the echo of a distant explosion. They usually occur by a clear sky and quiet air, and rarely also with wind and rain, with afternoons being more common than mornings and summer more frequent than winter. The apparent direction of origin is the southern to western area of the sky; a connection with earthquakes has never been demonstrated. One assumes the cause lies in the atmosphere itself; sometimes the effect is strong enough to bring planes of glass to tremor. The people almost everywhere take this as a sign of bad weather and, especially on the coast, as a sign of strong floods.

Outside of Europe, bangs of this sort can be commonly heard in Fundy Bay between Nova Scotia and New Braunschweig; and also there earthquake noises have been presented as an explanation for the odd tones; further suggested causes have been a strange echo of breaking waves, scratching of cliffs in the area of the upper crust of the Earth, and even noises produced by fish similar to the so called Drummer fish (Progonias chromis). More distantly it booms on the Congo and, above all, in the Ganges Delta, where it is known as the Barisal guns (named after the delta town of Barisal), and is mostly accompanied by heavy rain. The widest spread assumption links the bang with resulting from collapsing sandbanks.

Prof. Hahn-Königsberg considers all these sound phenomena as being in part noises from earthquakes, partly -and indeed mainly- as effects of local disturbances in temperature and pressure. However, before one can give a generalised and universally apt explanation, the question must first be resolved as to whether we are dealing here with primary or secondary events, that means whether the detonations develop independently or are reproductions or repercussions of other noises resulting from echoes -whether they be natural, for example distant thunder, avalanche collapses and the like, or artificial (artillery fire, explosions). The first assumption, that this is an independent acoustic phenomenon, is strongly supported by the facts that, in a whole set of the best controlled cases and despite careful natural research, none of the previously mentioned sounds could be detected far or wide, and also that observers have experienced an unusual natural process, the mist-puffers, on a number of occasions. Should, however, this be a secondary phenomenon, then there would still be enough unresolved questions which, as a long feature in the Schwäbischen Merkur of 2nd January, 1897 emphasized "make necessary further research on as wide a basis as possible, and this would be of interest to wider circles". Especially desired is an explanation regarding which particular atmospheric conditions must coincide, in order that witnesses get to hear the sounds mentioned above as they are perceived. From all the reports, it appears that the phenomenon of particular atmospheric conditions cause such acoustic effects. This sort of conclusion would be of great practical value, should the suspicion of Dr van den Broeck be substantiated, as the sound occurrences would have their causes in unequal electrical charges in the deeper and nearer surfaces of the crust of the Earth, or in their discharges, and that could be a sign of weather disruptive for mining. Their appearance would be a warning for miners not to enter the pit shafts during the critical following days. For this reason, the Verein für Geschichte des Bodensees und seiner Umgebung ('Association for the history of Lake Constance and its environs') announced itself ready, some 12 years ago, to collect further observational records and to scientifically analyse them.

The mysterious Seeschießen of Lake Constance, which we now what to look at somewhat more closely, is thus far not only known from the whole northern coast between Meersburg and Bregenz, but has also been reported from Rorschach and the heights of the mountain chain between Lake Constance and Thurtal, where it seems to come from between Friedrichshafen and Meersburg. It is also well known to the residents of inner Vorarlberg (about 33km from the nearest point of the shoreline as the crow flies) under the same name, and it is presumed to be a noise effect produced at the lake. It can be perceived by day as well as night time, almost always in beautiful weather, and it is known that the Föhn wind strongly influences the density and temperature conditions of the atmospheric layers. A report from Friedrichshafen appeared in Stuttgart's Neuen Tageblatt on 7th August 1908, and it says: "On a walk from here to Manzell along the so called Seeweg yesterday morning, I heard a number of dull rolling sounds like distant thunder between 9:15 and 9:30, and they seemed to come from the Swiss shore; as the sky was completely cloudless, I immediately thought of the summertime phenomenon of Seeschießen, which I have already heard over a number of years, and which is easy to distinguish from the detonations of distant shots. Seeschießen sounds most like, as said, the rolling of not too long, distant thunder. I sat on a shadowy bench near the edge of the water not far from Seemoos, and wondered at the motionless, mirror-like lake, with no ship in sight. It was 10 o'clock. I then noticed, at a distance of 600-800 metres from the shore, a 15-20m long wave in the water, which I at first held to be a growing bank of water plants; however, when I looked more closely, I saw the wave was nearing and ran parallel to the shore. In front of and behind this wave were 4 to 5 individual longitudinal waves at short distances from each other, but the water was otherwise completely quiet and flat; there was no swell and wake of the water to be seen, as would have been the case should the wash of a steamboat have been breaking against the shore, and they were also breaking before reaching the bank. The curious wave forced me to the thought, as to whether there was some connection with the Seeschießen, which had been heard half-an-hour earlier? Perhaps something caused by the tiefen Schweb, a deep pit in Lake Constance between Manzell and Uttwill, maybe an earthslide had occurred, and caused the Seeschießen and the aforementioned wave? I could see no other such waves." That quotation reminds one of what is termed the Seebär ('seal') in the western Baltic Sea. This name refers to a sudden swell and rise of the sea, which also happens by quiet weather and flat waters, and generally repeats itself; it is often stated that this apparently rare well is accompanied by odd sound effects. This Seebär has been said to have either a seismic or meteorological cause but -according to Prof. Hahn- the truth may lie in the middle.

Also on 18th September 1908, a dull, up to 2 second long subterranean rolling was heard in the area of Friedrichshafen on Lake Constance, and it was perceptible at intervals of between 4 to 5 minutes coming from the direction of Konstanz. It was suggested that this noise may have resulted from the less than 30km distant Swiss artillery range at Frauenfeld, where 3 artillery batteries were practising that morning, but the people at the lake did not accept this. It was a sound which could not be mistaken for the thunder of cannons. In any case, it contradicts the earlier, oft cited explanation of avalanche collapses in the nearby Säntis area as, on this day, no avalanches occurred either there or in Vorarlberg. The snow which had fallen in the mountains during the first falls of September were too light to have allowed for avalanches of such a magnitude; the first pronounced Föhntag, with the well known Föhn conditions in the air, was on the 16th September. Furthermore, a report about similar records of thunder-like sounds from the Spessart and Taunus, and the Ergebirge appeared in the Frankfurter Zeitung, and these could neither have resulted from explosions or artillery practise, as they were also widely heard on Sundays and public holidays.

It has already been stated by E Graf Zeppelin and FA Forel (printed in the 22nd edition of the journal from the association mentioned above) that electrical currents are present in Lake Constance, and these could give rise to the Seeschießen as a result of discharges. According to another opinion, the thunder-like noises come from the bed of the lake, and are caused by collapses or friction between conflicting strata. When one knows that observations over the years have shown sinkage of the earth beneath Lake Constance is continuing progressively, then this sounds plausible. Instruments have measured a sinkage of the Bregenz Harbour amounting to 102mm since 1906. Similar changes of the lake bed have also been detected in the area of the Neunburg Lake; for example, the ground bearing the village of Sugitz has sunk 132mm since 1882. Finally, the following newspaper report from 15th November 1908 should be mentioned: "A particularly strong example of Seeschießen was heard at Lake Constance in the morning today at 11 o'clock. Everybody on the lakeshore thought of an explosion, artillery fire or a sudden outbreak of thunder; a tremor was felt in Friedrichshafen as if it were an earthquake. It is presumed the tremor and noise were caused by a strong earthslide within the lake." In any case, the acoustic phenomena described above, both here and abroad, have not yet had their origins explained with certainty, and there is reason enough for strict scientific research to continue, and Kosmos seeks to provide encouragement towards this end.

An index of more of my translations of old Kosmos articles can be found at:

Kosmos Translations Archive

A number of Mesozoic (and post-Mesozoic) location summaries can be found at Localities.