*572 



SCIENCE. 



Science, 

 Curiosities 



is published in Dr Brewster's Journal of Science, vol. iik 

 p> 104. 



"About tliree months since, a bore for a well was com- 

 menced in Cannon Street, near Leith Fort. Nothing 

 particular was observed to occur in the course of the 

 workings, till Thursday the 28th ult. when the depth 

 of 87 feet from the surface had been attained, without 

 finding water. The bore had been sunk to this depth, 

 through seven feet of vegetable soil and sand, and 80 

 feet of a very stiff dark-coloured clay, containing im- 

 bedded, numerous rounded pebbles of quartz, chlorite 

 slate, hardened sand-stone, and coal. On the morning 

 of the 28th, at half-past six the two men, who had 

 hitherto wrought at the bottom of the bore, went 

 down, as usual, without lights, and commenced their 

 labours. In the course of an hour after this, while 

 driving their jumper (three inches broad), perpendi- 

 cularly through the clay, they suddenly found it slip 

 down about six inches, into an open space. Immedi- 

 ately,. through the hole, thus made by the jumper, there 

 issued with tremendous violence, and terrific noise, a 

 vast quantity of some air, which, rushing past the work- 

 men in the bore, ascended with such velocity, as to 

 carry along with it masses of the clay of considerable 

 size. The men below, instantly prepared to ascend, 

 and one having got into the bucket waa drawn up with- 

 out delay, and the rope again lowered for the other 

 one. He was seen to get into the bucket, and was 

 drawn up about thirty feet, when it was observed that 

 he appeared as if dead, and leaning over the bucket, so 

 as to be in danger of falling out altogether. The men, 

 therefore, above, fearful of his falling down and being 

 killed, instantly lowered the bucket again; and one 

 of them, ignorant of its being noxious air that had 

 burst from its confinement, slid down on the rope, still 

 without a candle, to see what was the matter with his 

 comrade ; on finding, however, his breathing beginning 

 to be affected, he returned to the mouth of the bore. 

 A lighted candle was now procured, and brought to 

 the mouth of the pit ; no sooner had its flame reached 

 the level of the ground, aver the bore, than the whole 

 air in the pit inflamed and exploded with a report as 

 loud as that produced by firing a large piece of ord- 

 nance;, the flames rose to. the height of forty feet and 

 more from the pit's mouth, and are described as having 

 been of a blue colour. A strong sulphureous odour 

 was immediately perceptible. 



It was not until two hours after this explosion, that 

 the unfortunate man was drawn out ; he was quite 

 dead his clothes were but little injured by the flames, 

 Those who were standing near, or over the mouth of 

 the bore, at the time of the explosion, got themselves 

 much scorched, and otherwise hurt. The whole neigh- 

 bourhood was violently shaken, but no wiutluws were 

 broken by the shock. 



No work was done in the pit for a week after this 

 occurrence ; but on the eighth day after, a candle was 

 again brought to the pit's mouth, when immediately a 

 second explosion, not quite so violent as the first, but 

 of the same character, ensued ; nor could the men ven- 

 ture down for several days ; and the gas collected in 

 such quantity, that, for about a week after this, it was 

 exploded every morning ; and the men found that the 

 quantity collected seemed to be greater in wet than in 

 dry weather. On continuing the workings at the bot- 

 tom of the bore, it was seen that the jumper used by 

 the deceased, and his companion,, had penetrated a large 

 cavity, situated immediately under the clay, and having 

 for its floor a stratum, of soft bituminous shale, called 



by miners blaize. In this cavity, therefore the Science, 

 size of which could not be exactly ascertained, the tkuK> s i s 

 gas seems to have been confined. By the 29th of 

 May they had got about ten feet below the surface of V *"Y"* 1 ^ 

 the shale, and still the gas continued to escape through 

 the shale from the floor of the pit ; in quantities, how- 

 ever so small, as not to prevent the miners from work- 

 ing all day ; they now complain more of the loath- 

 some sulphureous odour, which they still experience at 

 the bottom of the pit, than of any difficulty in breath- 

 ing. The pit is now 100 feet deep, and no water has 

 been found. Its mouth is situated about fifty yards 

 from, and is elevated about twelve feet above high 

 water mark." 



DYNAMICS. 



J. Experiment showing the Equal Action of Gravity on 

 Light and Heavy Bodies. 



In order to exhibit the equal action of gravity on Experiment 

 light and heavy bodies, it was formerly necessary to showing the 

 have recourse to the vacuum of an air-pump, and the ( l ual ac - 



celebrated experiment of the guinea and the feather u . on of ra- 



11 L LI. vi ty on 



falling with the same velocity in the receiver, has been j- ht aru j 



displayed for centuries. heavy 



The late M. Benedict Prevost devised the follow- bodies. 

 ing simple experiment, which proves the equal action 

 of gravity by proving that the retardation in the fall 

 of light bodies arises solely from the resistance of the 

 air. Place a piece of thin paper on the bottom of a 

 small box, of such a weight that in falling the bottom 

 of it will always keep lowermost. Let the box now 

 fall from the height of eight or nine feet above a 

 cushion, and the paper and the box will both reach the 

 cushion at the same time, just as if the paper had clung 

 to the bottom of it. If the same piece of paper is allow- 

 ed to fall by itself from the same height, it will flutter 

 slowly and obliquely to the floor. The experiment 

 will succeed equally well if the piece of paper is placed 

 upon a crown or half crown piece without using a 

 box. The rapid descent of the paper when placed on 

 the box is in na way owing to any adhesion between 

 it and the bottom of the box, but to the circumstance 

 of there being no air to obstruct its descent, the ad- 

 vance of the box in front of the paper having the same 

 effect as if there was a perfect vacuum before the piece 

 of paper. A little box of lead or piece of lead with 

 round edges is best for making the experiment. 



One of the most curious dynamical experiments- 

 which has been witnessed in modern times, is the de,- 

 scent of trees with the rapidity almost of lightning 

 along the celebrated slide of Alpnach, of which we 

 shall give a full description under the article SLICE in 

 Vol. XVI II. 



ELECTRICITY AND GALVANISM. 



In our articles on ELBCTRICWY, Vol. VIII. p. 411, 

 and GALVANISM, Vol. X. p. 79, w have given such a 

 copious detail of the remarkable experiments which 

 these two sciences embrace, that there is little occasion 

 for tny resumption of the subject under the present 

 article, unless to give an account of some of the more 

 popular discoveries which have been made since these 

 articles were printed. 



1. On the Pyro- Electricity of the Tourmaline. 

 The general phenomena of the pyro-electricity of 



