2 50 



NATURE 



{July ^, 1878 



while the north westerly current is on the north-west side, or as it 

 is sometimes termed, the back of the storm. In the case of an anti- 

 cyclone the whole thing is reversed. The two currents pass each 

 other on their respective right hands. This enables the high glass on 

 the right side of each to coincide with one another. The two 

 winds instead of dragging away from each other, are pushing 

 against each other, and form a heap of air round which they 



Cycl<vi0 



>^ 



CvcLONK. — A A, a north-east wind; b b, a south-west wind; w, westerly- 

 drift of A A due to difference of absolute velocities of earth's motion at 

 different latitudes ; W, effective part of w, in producing rarefaction at 

 r; e', effective part of b as above. Remit, rarefaction in centre of 

 cyclone. 



w 



Anticyclone 



Anticvcwne. — Mutatis mutandis as cyclone. Result, condensation at 

 centre of anticyclone. 



rotate^ not necessarily in the opposite direction to that of the 

 cyclone. It would be interesting to know whether an anti- 

 cyclone travels from north-east to south-west. Whether it does 

 so or not I do not know ; but this is what would seem to follow 

 if the above imperfectly-stated theory is a correct one. 



Eustace Barham 



Whirlwind 



As meteorologists appear to be taking much interest in whirl- 

 winds and waterspouts, you will perhaps allow me to offer you 

 a few notes respecting a whirlwind that passed over a moun- 

 tainous part of Northumberland on April 14, 1869, and left 

 indisputable evidence of the direction in which it revolved, a 

 fact of some importance, and one in general so difficult to ascer- 

 tain, that after much research I have never yet met with a 



description of either whirlwind or waterspout that can be con- 

 sidered satisfactory in this respect. 



I have long held the opinion that the smaller whirlwinds and 

 waterspouts are of the same nature, and follow the same laws, 

 as the greater cyclones, although Sir Wm. Reid, at p. 461, vol. i. 

 of his *' Law of Storms," is of a contrary opinion, founded on 

 observations of waterspouts at sea, where it is extremely difficult 

 to judge by the eye in which direction a spout is rotating. 

 The cases where, as in America, attempts have been made to 

 settle this point by the direction of trees thrown down by the 

 ^^ hirlwind are very unsatisfactory ; and there is nothing definite 



X 



^ 



on this head to be met with in the description of upwards of 

 three hundred whirlwinds described by Peltier in his work "Sur 

 les Trombes." 



The 14th of April, 1869, was exceedingly wild and stormy, 

 and so dark at mid -day that we could scarcely see to write at a 

 meeting of churchwardens in the vestry of Hexham Abbey 

 Church, Having heard of the whirlwind at Sweethope, about 

 ten miles north of Hexham, I went thither in July, 1869, ac- 

 companied by my friend Dr. James Smith, of Newcastle-upon- 

 Tyne. We passed the night at Sweethope Farm (a), and 

 examined the course of the meteor carefully. Masons were still 

 engaged rebuilding a stable and boathouse (c) which stand at 

 the northern extremity of the embankment that separates the 

 larger from the smaller lake, from which issues the River 

 Wansbeck, that flows past Morpeth, about twenty miles to the 

 eastward. 



The whirlwind was first noticed by the inmates of Mr. Rob- 

 son's house, A, as it passed a small plantation on a hill at b, and 

 was seen to travel in a north-westerly direction across the road 

 at D, along the embankment between the two lakes, over the 

 boathouse, c. From this point it passed a plantation of young 

 trees, through which it cut a broad lane, and afterwards over- 

 turned a haystack. 



Mr. Robson informed me, in a letter, that "trees were torn 

 up by fifties, some broken off about midway, and carried a con- 

 siderable distance in the air. Stones were turned up that would 

 have taxed the powers of three or four strong men. Several 

 sheep and lambs were lifted up into the air and killed by the 

 fall; others were carried up, and, falling into the lake, were 

 drowned. There was a tremendous thunderstorm, with forked 

 lightning and very large hailstones. It did not travel very fast, 

 and was like a large volume of smoke." 



The boathouse was entirely unroofed and the nails drawn out 

 of the planks of a floor of a room in the upper part of the 

 building. The small plantation at A is 812 feet above the sea- 

 level. Nothing was seen or heard of the whirlwind beyond the 



limits of the diagram, which is copied from the Ordnance Survey 

 Maps on the scale of an inch to a mile. 



So far, the Sweethope whirlwind presented only the usual fea- 

 tures of its class, and we were about to depart, after some good 

 sport among the fish in the lakes, when Mr. Robson's son men- 

 tioned to me that the whirlwind, in crossing the road (at d), had 

 thrown part of the wall into the road and another part into the 

 field, a significant fact of which we at once proceeded to examine 

 the details. At the point D in the diagram the wall runs m a 

 direction nearly north by east, and has been about four feet 

 high. At the southern end we found about two feet of the 



