As if on purpose to confuse our already very vague ideas about thunderbolts, there is one special kind of lightning which really seems intentionally to simulate a meteorite, and that is the kind known as fireballs or (more scientifically) globular lightning. A fireball generally appears as a sphere of light, sometimes only as big as a Dutch cheese, sometimes as large as three feet in diameter. It moves along very slowly and demurely through the air, remaining visible for a whole minute or two together; and in the end it generally bursts up with great violence, as if it were a London railway station being experimented upon by Irish patriots. At Milan one day a fireball of this description walked down one of the streets so slowly that a small crowd walked after it admiringly, to see where it was going. It made straight for a church steeple, after the common but sacrilegious fashion of all lightning, struck the gilded cross on the topmost pinnacle, and then immediately vanished, like a Virgilian apparition, into thin air. A few years ago, too, Dr. Tripe was watching a very severe thunderstorm, when he saw a fireball come quietly gliding up to him, apparently rising from the earth rather than falling towards it. Instead of running away, like a practical man, the intrepid doctor held his ground quietly and observed the fiery monster with scientific nonchalance. After continuing its course for some time in a peaceful and regular fashion, however, without attempting to assault him, it finally darted off at a tangent in another direction, and turned apparently into forked lightning. A fireball, noticed among the Glendowan Mountains in Donegal, behaved even more eccentrically, as might be expected from its Irish antecedents. It first skirted the earth in a leisurely way for several hundred yards like a cannon-ball; then it struck the ground, ricochetted, and once more bounded along for another short spell; after which it disappeared in the boggy soil, as if it were completely finished and done for. But in another moment it rose again, nothing daunted, with Celtic irrepressibility, several yards away, pursued its ghostly course across a running stream (which shows, at least, there could have been no witchcraft in it), and finally ran to earth for good in the opposite bank, leaving a round hole in the sloping peat at the spot where it buried itself. Where it first struck, it cut up the peat as if with a knife, and made a broad deep trench which remained afterwards as a witness of its eccentric conduct. If the person who observed it had been of a superstitious turn of mind, we should have had here one of the finest and most terrifying ghost stories on the entire record, which would have made an exceptionally splendid show in the Transactions of the Society for Psychical Research. Unfortunately, however, he was only a man of science, ungifted with the precious dower of poetical imagination;