Part 3 of PhD student Geoff Hellman’s in depth study of the eruption of the Laki volcano and the effects it had worldwide. He has kindly allowed us to publish some of his writing.
Violent Storms and Great Balls of Fire
According to the Abbot van der Meulen, who was writing from Roesbrugge, West Flanders:
“The year with the nicest weather was 1783; it was permanently or nearly (always) sunny from 8 o’clock in the morning till evening, during 103 days”.
Northern Europe, because of its latitude, could usually expect cooler weather than the south, and 1783 saw a period of intense heat in some areas, making the summer western Europe one of the warmest for the past 300 years. But as we shall see, between the months of June and September, there were many reports of unusually violent storms of torrential rainfall accompanied by thunder, lightning, hurricane force winds, hail and the occasional fireball. The cause of this was the high level of evaporation from the ground’s surface brought about by the hot fogs, which charged the atmosphere with an abundance of water vapour. The air was also loaded with considerable quantities of fine volcanic dust, and this provided a source of highly efficient condensation nuclei.
The following is an extract of a letter from Avignon, dated 5th August, 1783:
“Several letters from the neighbouring parts make mention of the storms which have multiplyed (sic) of late, and done great damage in the country places. The 22d of last month, at St. Esprit, there was a storm which destroyed the harvest for the space of a league. The hail-stones were of the size of a hen’s egg; and their irregular form cut the vines and trees to pieces. A naturalist remarked, during the storm, a very extraordinary phenomenon – A girl who was spinning silk, feeling herself struck on the head with a hailstone, put her hand to the part, and found her cap on fire, which she immediately tore off, and flung away. As at that moment there was neither thunder nor lightning it was presumed that the fire had flashed from the collision of two hailstones which had hit each other on the girl’s head. “(Chelmsford Chronicle, 29 August 1783
“Much about the same time, there was also a terrible storm at the Bouschet (sic) in this country, where the hail fell with such violence, that part of that territory was totally ravaged. A peasant who was overtaken with the storm in the open country was knocked down by a hailstone of an enormous size, and died in three hours.” (Chelmsford Chronicle, 29 August 1783)
Two further reports from the Chelmsford Chronicle testify to the ferocity of the storms:
“A letter from Carmarthen, in South Wales, says, that on Sunday the 31st ult. they had a tremendous storm of thunder and lightning; many of the houses were unroofed, and the rain came down so heavy, that the damage done is very great in the parts adjacent; many head of cattle were found dead in the fields, and two labourers and their wives who lived in little huts were found dead.“
“Friday last there was a most tremendous storm of thunder and lightning in the neighbourhood of Grantham; at Foston, a ball of fire entered the house of Mr. Neale, made its way through the tiles, struck down some of the family, and very much shattered the walls; it then took its way through the window, which was broken to pieces; and entered the adjoining house and burnt a woman in a most shocking manner” (Chelmsford Chronicle, 19 September 1783)
A report from Cracow, Poland, dated 27th of July stated that:
On the sixth instant the storm of thunder and lightning was the most awful ever known in this country. Some people counted 200 claps of thunder with almost incessant flashes of lightn”ing, by which 12 houses were set on fire, and several churches, with the Starost’s palace, much damaged. Next day some people were found dead in the streets.”
Dead Insects, Fish, and Falling Leaves
Apart from Iceland, there were many places in Europe, notably those bordering the North Sea and the Baltic regions, whose vegetation suffered from the effects of the dry fog or acid rain.
Areas of severe defoliation
The following newspaper and journal extracts indicate that the fog caused severe damage to some of the vegetation in the British Isles and Europe. For example:
Sir John Cullum writing from Hardwick House, Suffolk, on 10th of November 1783, said that on the morning of 23rd of June there was an unseasonable frost which:
“…produced some remarkable effects. The aristae of the barley, which was coming into ear, became brown and withered at their extremities, as did the leaves of the oats; the rye had the appearance of being mildewed; so that the farmers were alarmed for those crops. The wheat was not so much affected…. Some weather, that was cold for the time of year, had preceded this frost. On the 21st the thermometer had, at no time of the day risen to 60° (15.5°C); on the 22nd, at ten at night it had sunk to 50° (10°C).”
He goes on to relate that the tips of the leaves of the larch, Weymouth pine and hardy Scotch fir were withered and made a poor showing for the rest of the summer. His sheltered ash trees were badly damaged, the crop of a walnut tree was ruined, whilst a standard peach tree, cherry, filbert and hazel-nut trees shed their leaves as though it were autumn. Other plants including a barberry-bush, blackthorn and sweet violet had shrivelled and discoloured leaves and looked as though a fire had been lighted near them. However, an exotic mulberry-tree, fig-tree and vine were affected very little.
Similar reports appear in other papers from Eastern England. The Cambridge Chronicle speaks of intense cold on the night of 23rd of June and on the following day all the grazing had dried up and was like hay to walk upon, whilst beans had turned a whitish colour and their leaves appeared as if dead. (Cambridge Chronicle and Journal, Saturday >July 5th, 1783).
In a letter dated 25th of June and published in the Ipswich Journal it speaks of different varieties of grain, viz. wheat, barley and oats appearing very withered, but the grain inside, being protected by their husks, was not. (Ipswich Journal, Saturday July 12th, 1783)
It seems unlikely that a frost would cause some trees to shed a large quantity of leaves, leave an exotic mulberry tree undamaged whilst attacking hardy coniferous trees, albeit only damaging the tips of their leaves. These symptoms, when taken together with pasture drying up overnight and Cullum’s scorched bushes, point not to frost damage, but to an acid or halogen attack, leaves being particularly susceptible as they easily absorb sulphur dioxide, fluorine and hydrochloric acid.
van Swinden reporting from the Netherlands said:
“In the morning of the 25th day (June) the fields showed a very sad appearance. The green colour of the trees and plants had disappeared and the earth was covered with drooping leaves. One would easily have believed that it was October or November… not all plants were equally affected; certain uninjured ones remained standing.”
van Swinden’s compatriot, Sebald Justinus Brugmans, published a book in 1783 where he lists over 200 species of plants which were affected to a greater or lesser extent by the haze.
An extract of a letter from Emden, dated 12th July states that:
“The thick dry fog that has so long prevailed, seems to have spread over the whole surface of Europe… in some places it withers the leaves, and almost all the trees on the borders of the Ems have been stripped of theirs in one night.” (Gazette de France, No. 60, pp. 269-270, 29th July, 1783; Ipswich Journal, 9 August, 1783)
Nevertheless, there was some good news. There were accounts from eastern and southern Europe where beneficial effects were attributed to the dry fog. For instance, there was a vigorous growth of vegetation in parts of Italy and record grape harvests were reported from Germany, Austria and Hungary, fruit of all kinds from the Banat, whilst in Poland, the corn was harvested at the beginning of July, an unprecedented event there.
However, it was not only vegetation that felt the fog’s harmful effects, but myriads of insects that appear to have been killed by the absorption of acid particles through the leaves. According to van Swinden:
“…this haze made a great slaughter of insects, especially of fleas, which settle on leaves of trees. When the leaves themselves were damaged, the insects of the trees, which were not injured by the haze, were killed exclusively as they remained intact to the leaves.”
The following account appeared in The Caledonian Mercury, Saturday July 5th, 1783.
“Wednesday night we had here a great storm of thunder and lightning, accompanied by a very heavy fall of rain… We hear, that next morning, after the storm of thunder and lightning here, there were found in the dam above the saw-mills on the water of Leith, a number of dead fish of different kinds floating on the surface of the water supposed to be killed by the lightning.”
There may be two reasons for the death of these fish. Firstly, the body of water they were in was struck by lightning and they were sufficiently near the strike for the electricity not to have spread out and been dissipated. Secondly, acids which may have been dry deposited and accumulated on the land for some time, may have been washed into the water by the storm, thus lowering its pH level and making it toxic.
In Italy, however, they were having problems of a different sort. Gennari, writing from Padua, reported on a fatal illness which was thought to be contagious had attacked some cattle that had arrived from Dalmatia. He goes on to state that the disease also infected beasts from some of the country villages. Although the peasants believed their animals had contracted the sickness from the Dalmatian cattle, he speculates that the reason lay behind their having been fed on bad fodder and tree leaves during the winter owing to the lack of hay caused by a drought the previous summer.
“Then when the damp and always foggy spring came, the hungry cattle were sent to pasture on fresh grass on which they gorged themselves, being greedy and (the grass) ever so tender, their insides were affected by a malevolent disorder that then developed into the current illness. It was observed that the cattle which had been fed on good hay, have not, up till now, been affected by the bad influence.”
It is quite possible that this was a cattle disease such as coccidiosis, which is spread through damp grazing areas, or black leg which can prove fatal within twelve to forty eight hours after infection, but it seems more likely that the cattle died through ingesting grass contaminated by acid volatiles, especially as those on good hay were not affected.
Next week: Social Responses