July 19, 1883] 



NATURE 



269 



of our country, and consequently any records or facts 

 connected with them have a charm both for the forester 

 as well as for the general reader. Dr. Brown's book on 

 " The Forests of England " is therefore far from dry 

 reading, treating as it does of such well-known forests and 

 parks as Sherwood, Epping, Dean, and the New Forests, 

 Woolmer, Whitlebury, Windsor, Malvern, Cannock, and 

 Hatfield Chases, &c. 



A good deal of attention is being directed at the present 

 time to the preservation of our forests in their natural 

 beauty, and we should hope that Dr. Brown's books will 

 at least have the effect of sharpening the interest of those 

 who have hitherto been indifferent about the works of 

 draining and planting that are always ready to be put for- 

 ward as improvements, but which are for the most part of 

 a character that should not be allowed to be carried out 

 without deep and serious consideration by those qualified 

 to advise. 



" French Forest Ordinance " is a book of a more practi- 

 cal character than the preceding, inasmuch as it deals 

 more with forest treatment and legislation in France, 

 nevertheless it contains much of interest. The following 

 extract from Chapter III. will explain : " It has been men- 

 tioned that the forests were exploited at that time [middle of 

 seventeenth century] on a system of exploitation known 

 as jardinage or furetage. The method of exploitation 

 so designated is that which is generally followed in the 

 management of woods in England, and of forests in our 

 colonies — felling a tree here and there, and leaving the 

 others standing — and is called in French forest economy 

 jardinage, or gardening, from its similarity to the proce- 

 dure of a gardener gathering leeks, onions, turnips, 

 carrots, cabbages, or cauliflowers — taking one here and 

 there, not at haphazard, but with some principle for his 

 guidance — it may be to thin them — it may be to gather in 

 the mature, and leave the others to grow ; and called 

 furetage, or ferreting, from the similarity of the woodman's 

 procedure in seeking out what trees to fell — to what is 

 called, from the conduct of a ferret, ferreting out what is 

 wanted when it does not at once appear." 



LETTERS TO THE EDITOR 



[The Editor does not hold himself responsible for opinions expressed 

 by his correspondents. Neither can he undertake to return, 

 tr to correspond with the writers of, rejected manuscripts. 

 No notice is taken of anonymous communications. 



[ The Editor urgently requests correspondents to keep their letters 

 *s short as possible. The pressure on his space is so great 

 that it is impossible othe/ivise to insure the appearance even 

 of communications containing interesting and novel facts.] 



"Waterspouts" on the Little Bahama Bank — Whir'- 

 wind at Grand Cayman 



We have received the following communication, by an officer 

 of H.M. surveying vessel Sparrowhawk, employed in the West 

 Indies, from the Hydrographer to the Admiralty : — 



Being much interested in the subject of waterspouts and their 

 formation, and having failed to find anything about them in the 

 works of recognised authorities, I venture to record some per- 

 sonal experiences together with what information I have been 

 able to collect from the inhabitants of Ataco and the adjacent 

 bays. 



During the summer months waterspouts are common on the 

 Little Bahama Bank. I have seen seven at once in water vary- 

 ing from ten feet to over a hundred fathoms, and I am informed 

 that fifteen have been observed. 



I have noticed that the first movement which eventually pro- 

 duces a waterspout is a whirlwind on the surface of the water 

 gradually increasing in velocity of rotation and decreasing its 

 diameter as it travels alone before the prevailing \\ ind. The 

 spray is lifted to a height of from five to ten feet, and then gradu- 

 ally melts away, assuming the appearance of hot air, which is 

 visible (still rotating) to a similar height above the .spray. A 

 motion amongst the clouds soon becomes apparent, a tongue is 

 protruded, and the spout becomes visible from the top downwards. 



On one occasion a portion of a spout appeared for a moment 

 in mid air above the disturbance on the surface of the water. 



Although these appearances are commonly called "water- 

 spouts," I am informed by men who have been caught in them 

 that they contain no water, and should be properly called "wind- 

 spouts ;" the small fore-and-aft-rigged schooners that ply on the 

 bank do not fear them, although a prudent captain would probably 

 shorten sail to one. I have been unable to hear of an accident 

 having occurred through a vessel being caught in a waterspout. 



They frequently cross the land, but no water falls ; they take 

 up any light articles, such as clothes spread out to dry, straw, 

 &c , that happen to be in their course, but have never been 

 known to carry anything along with them for a distance. 



At Grand Cayman Island I noticed a whirlwind on the water, 

 of somewhat similar appearance to those of the Little Bahama 

 Bank just mentioned, though there was no cloud above it ; the 

 place where it appeared was a sheet of shoal water between the 

 fringing reef and the shore, about one cable in breadth and 

 three to ten feet deep. The whirlwind passed about fifty yards 

 from where I stood ; its estimated diameter was fifteen feet, and 

 it whirled rapidly from left to right ; the spray was lifted from 

 the surface in a revolving sheet to a height of ten feet, but ap- 

 peared to get thinner towards the top, and gradually melted away 

 till it looked like the air over a boiling cauldron visible to a 

 height of ten feet above the spray. I estimated its rate of pro- 

 gression at five knots ; the wind was light (force 2). The whirl- 

 ing spray made a continuous hissing noise like a fast boat under 

 sail passing close ; it caused no particular wave on the beach 

 and left no wake ; its character was unchanged for half a mile, 

 when I lost sight of it by its passing a point. 



The inhabitants informed me that in their memory several 

 whirlwinds had passed, but none had been known to cross the 

 land. Morris H. Smyth 



A Remarkable Meteor 



A METEOR was seen at Hendon on the 6th inst, at 8.53 p.m., 

 in a clear sky, and broad daylight. The course by compass was 

 from north-east to east, at an altitude of about 27 above the 

 horizon when first seen, and 22° when it disappeared, after 

 being visible six or seven seconds. I drew the attention of a 

 friend, in whose garden we were standing, to it. He saw it 

 about three seconds, and compared it to a stream of fire. I 

 learnt later that it was also seen by parties boating on the waters 

 at the Welsh Harp, but could not get any particulars beyond the 

 fact that it was seen. Its passage appeared attended by intense 

 combustion. It first appeared as a circular ball of fire, but 

 speedily lost a spherical shape, and became pointed, resembling 

 somewhat a spear head, as though the change in appearance were 

 due to the resistance of the atmosphere. From a deep red at 

 first it became of a decided golden colour, to change to a brilliant 

 white just before or as it disappeared. There was nothing 

 special about the disappearance. P. F. D. 



London, W. 



The Function of the Sound-Post in the Violin 



I read with much interest the part of Dr. Huggins's paper 

 which relates to the above subject, having myself tried numerous 

 experiments in the same direction. The conclusions I arrived 

 at do not so much differ from those set forth in the paper, as that 

 I venture to tbink they go a step further. It is on this plea 

 that I ask for the acceptance of the following observations : — 



It is undoubtedly true that the sound-post of a violin does 

 communicate the vibrations from the belly of the instrument to 

 the back ; but, as will be hereafter seen, these vibrations are not 

 of an order to reinforce the sound except to a limited extent. By 

 far the most important function of the sound-post is that it acts 

 as a prop to the belly in such a position and in such a manner 

 as to enable the latter to give out a more resonant order of 

 waves. The back may, and does, give out a modicum of sound, 

 but it is especially the belly which becomes more resonant under 

 the influence of the prop than without it. 



In the first place, when the sound-post is removed, the belly 

 of the violin is then an uninterrupted elastic table with a vibra- 

 tion rate of its own, its greatest elasticity being just at the part 

 where the bridge is situated. Now it may safely be predicted, 

 without resorting to experiment, that this specific rate of vibra- 

 tion of the belly itself will interfere with the varying rates of 

 vibration communicated to it by the strings. That it is so, how- 

 ever, I have conclusively proved by actual experiments in great 



