Observations on the Lumen Boreale, or Streaming on Oct. 8, 1726, by the Reverend Mr. W. Derham, F. R. S.

I. Observations on the Lumen Boreale, or Streaming on Oct. 8, 1726, by the Reverend Mr. W. Derham, F.R.S. Although the Lumen Boreale, or Streaming hath been a common Phænomenon, ever since the surprising one, Mar. 6, 1715, 16, and as such, would not deserve to be taken notice of; yet in this of Oct. 8, there were not only such surprising, but different Circumstances, that, I hope, the Royal Society will receive Accounts of them from many Hands; which may enable the skilful Meteorologists to find out their Cause. For the clearer proceeding in my Relation, I shall observe, that there are two sorts of Streamings, which I have taken notice of; one, by way of Explosion from the Horizon; the other, by opening and shutting, without such Shootings up, and swift Dartings, as those were which appeared in the Lumen Boreale before spoken of. Of the latter sort chiefly, was this last of Oct. 8: in which, altho' the Streams, or Spires, or Lances, or Cores or, what shall I call them?) were as large and remarkable as in the former; yet they exhibited themselves principally by the vaporous Matter opening and shutting, as if a Curtain had been drawn and withdrawn before them. The first View I had of this Phænomenon, was precisely at Eight o’Clock in the Evening: At which time, all I saw, was a long narrow Fascia, like a white ragged Cloud, extended crois the Heavens, from W. b. S. to E. b. N. which in a few Minutes began to emit some Streams, and then disappear'd: Which was succeeded by much Streaming in the Northerly Parts; and in a quarter of an Hour it began to reach other Points also; and soon after that, it streamed all round in the Southerly, Easterly and Westerly Parts as much, or nearly as much as in the North. Which was a thing I never had seen before in these Phænomena. Fig. 1. These Streams, or Cones, were for the most part pointed, so as to make the Appearance of flaming Spires, or Pyramids; and some others were truncated, and reach'd but half way: Some also were longer, and some shorter; some of which had their Points reaching up to the Zenith, or near it, where they formed a sort of Canopy, or thin Cloud, sometimes red, sometimes brownish, sometimes blazing as if fired, and sometimes emitting Streams all round it, which at that time gave it the appearance of such a Star as our Knights of the Garter wear on their Breasts. This Canopy was manifestly formed by the Matter carried up by the Streaming on all parts of the Horizon: Which Matter sometimes seem'd to ascend with some force, as if impell'd by the Impetus of some explosive Agent below, as I have said it was in the Streaming of March 1715, 16, and which I gave the Society a large and particular Account of soon after. This forcible Ascent of the streaming Matter, gave a Motion to the Canopy, sometimes a Gyration, like that of a Whirlwind; which was manifestly caused by the Streams striking the outside Parts of the Canopy, as in the Figure: But when the streaming Matter hit the Canopy in the Middle, all was then in Confusion. These two Particulars, namely, the Streaming all round, in all Points of the Horizon; and the Canopy in and near the Zenith, are what were taken notice of in all Parts of England, that I have met with any Accounts from; particularly, in Northamptonshire, Staffordshire, Oxfordshire, Wiltshire, Berkshire, Middlesex, Somersetshire, and Essex, and in divers Parts beyond Sea. The Reverend and Learned Mr. Waffe gives me this Account of its Appearance at Aynho in Northamptonshire, That at 7 h. 20' p. M. he saw an Arch somewhat curved, like a Rainbow at first, and about half the Breadth of the Rainbow, and yellow; which in about ten Minutes began to twist, and make an Angle at the Zenith: That one End of it was pretty much to the East, and not directly to the North; and the Western End deflected as much to the South: That it remained after the Twist, at the Zenith, without any great Motion, not a quarter of an Hour. After which, the Rods arose on all sides, from the Horizon to the Zenith, the upper Points seeming to move thro' a sort of Vortex quite out of our Atmosphere: Which Rods, he thinks, rose perpendicularly from the Horizon, but seemed to converge towards the Zenith, according to the Rules of Perspective, by their Angle then being less than their Basis at the Horizon: That a Redness was perceived, which, he thinks, was strongest towards the West; which Colour did not appear till the Arch brake into several Pieces, and overspread the Heavens with a thin faintish Fire, thro' which they saw Jupiter very clearly. This Account of Mr. Waffe's may shew, how the Phænomenon was in England; by reason most of the Accounts I have met with, concur in the main with his But in the more Southerly Parts of Europe, I take it to have been somewhat different. The Newspapers tell us from Staffhausen, that on the 19th of October there was a great Alarm in many Parts of Switzerland, on account of a great Light seen in the Air, from 7 o’Clock till Midnight; which was supposed to be the Reflection of some great Conflagration. At Bern, every body thought there was a Fire in some part or other of the City or Neighbourhood. At Neufchatel, the Alarm-Bells were rung, and the Governour several Hours on Horseback, to give Orders, &c. as in Cases of Distreets. All which they heard afterwards, was only an Aurora Borealis.” And from Florence, my ingenious and curious Friend Sir Tho. Dereham sent me this Account, “As to the Lumen Boreale, which appear’d in these Parts on Oct. 8th last, I saw it myself in the following manner: It was one Hour and half after Sun-set, when I was passing thro’ a Piazza in this Town, that I discover’d the Phænomenon, that seem’d one Mile long, and three quarters of a Mile broad, of an almost perfect Oval Figure, hanging North and North-East to us: The Edges of it were of pale light Colour, like the first Dawn of the Morning; and towards the Center, it encreas’d its fiery Colour; so that in some Places it look’d as the Fire of a Furnace; but in the very Center, and many adjacent Parts, it was like a red-hot Iron growing cold, that seems bloody. For a good while I could perceive no Motion in it; but after a quarter of an Hour, I discover’d a general slow Motion backwards and forwards, like that one sees of the Circulation of the Blood in the Tails of Fishes, by the help of the Microscope, but no manner of Darting; info- much that in another quarter of an Hour it vanished imperceptibly, just as a Rainbow, and the Air grew dark again, that was so luminous before, that one might read a Manuscript by the same. It is very remarkable, that at Fiesole, a Town within a short Mile of this, the Phænomenon seem'd to those Inhabitants, to be between them and us, and they thought our Town was burning: Whereby it appears not to have been very deep, nor very high; Fiesole standing upon a Hill half a Mile high, and to the North-North-East of this Town. To these Observations of my self, and some of my Correspondents, I shall add two or three things more, before I enquire into the Cause of the Phænomena. One thing that was taken notice of in most Places, was, That in some part of the greatest Streaming, the Vapours between the Spires, or Lances, were of a Blood-red Colour. That which I observ'd, was, That about half an Hour after Eight o'Clock, the Vapours towards the South-West were very dense, and for some time red. And not long after, the like Redness arose in the North-East, and the other gradually went off. Both which gave those Parts of the Atmosphere the Appearance of blazing Lances, and bloody-colour'd Pillars. Another thing I took notice of, was, a strange Commotion, and Working among the Streams, as if some large Cloud, or other Body was moving behind them, and disturb'd them. In the Northerly and Southerly Parts the Streams were perpendicular to the Horizon; but in the intermediate Points they seem'd to decline more or less one way or other; or rather to incline towards the Meridian. As for the Weather, the preceding Day was cloudy, with an Hoar-Frost in the Morning; but it clear'd up, and grew warmer afterwards; but towards the Horizon, very vaporous. And the next Morning (after the Streaming before Sun-rising, the Air was full of Vapours, with divers thin vaporous Clouds, some of a lucid brown, some reddish, which I took to be Remains of the Streaming, which, I was informed, continued all Night. As for the Cause of these Phænomena, I take it to be from the same Matter, or Vapours, which produce Earthquakes: And that for these Reasons: First, Because some of these Phænomena have been followed by Earthquakes As that which Stow gives an Account of in his Annals, in the Year 1574, on Nov. 14, in which he saith, were seen in the Air strange Impressions of Fire and Smoak to proceed forth of a black Cloud in the North towards the South. That the next Night following, the Heavens from all parts did seem to burn marvellous ragingly, and over our Heads the Flames from the Horizon round about rising did meet, and there double and roll one in another, as if it had been in a clear Furnace. And after this (he tells us) followed on the 26th of February, great Earthquakes in the Cities of York, Worcester, Gloucester, Bristol, Hereford, and in the Countries about, which caused the People to run out of their Houses, for fear they should have fallen on their Heads. In Tewksbury, Breedon, &c. the Dishes fell from the Cupboards, and the Books in Mens Studies from the Shelves: With more to the same purpose. So this last (in October) was preceded by that fatal Earthquake at Palermo in Sicily, and succeeded by one in England, on Tuesday, October 25, following. This, I hear, was perceived in London, and was very considerable derable at Dorchester, Weymouth, Portland, Portsmouth, Purbeck, and divers other Places in Dorsetshire, that it caused the Doors to fly open, shook down Pewter off the Shelves, and was felt in some Ships that lay in the Harbours. 2. Another Reason is, That I am assur'd by an ingenious sensible Gentleman of my Acquaintance, that as he was viewing this Appearance, on the Top of his House at Little Chelsea, he plainly perceived a Sulphureous Smell in the Air; and that another Person did the same, on the Top of another House near him. 3. Another thing which concurs with what hath been said, is, That I am assured from several Persons, that an Hissing, and in some Places a crackling Noise was heard in the time of the Streaming, like to what is reported to be often heard in Earthquakes. And now, for a Conclusion, I shall remark two things upon what hath been said. 1. That it may help the sagacious Meteorologist to resolve several Difficulties relating to these Northern Lights, to observe, that what was Streaming or Darting in our Northern Parts, was only a remarkable Light, or Blaze in Italy, and the Southern Parts, if I take Sir T. Dereham's and the News-Papers Accounts right. 2. If those Phænomena have the same Origine that Earthquakes have, that then they are, doubtless, of great use to the Peace and Safety of the Earth, by venting some of that pernicious Vapour and Ferment that that is the Cause of those terrible Convulsions, which Earthquakes are accompanied with. I forgot (when I described the Canopy or Corona) to say, that it did not rest in one place; but changed its Position sometimes higher near the Zenith, and then towards the East, and South-East, 10 or 15 Degrees, and then back again nearer the Zenith, according as the darting Matter directed it: But I do not remember, that this Canopy was at any time directed towards the Western Points. In most of the Northern Lights that I have seen, there generally was a dark Bank of Vapours, circular on the Top; but whether this of Oct. 8, had any such Arch, I could not see at Upminster, where I was surrounded with Trees.