Slates have recently been employed in France for hastening the ripening of fruits. The effect was first observed on a slate roof; since which the slates have been placed beneath the fruit on walls. * * * * * _Hatching Eggs by Hot Mineral Waters._ This curious process has lately been practised with great success in the south of France. It consists in putting the eggs into a small basket, suspending the latter in a stove heated by the hot mineral water, and turning the eggs every day. The first trial was attended with success, and no failure was experienced in four repetitions of it. * * * * * _Lake Erie._ The height of Lake Erie above the Atlantic Ocean, has been ascertained to be 565 feet. The barrier which contains it is so low, that, were it only to rise six feet, it would inundate, on its northern and western borders, seven millions of acres, now partly occupied by towns, villages, and farms; and it is estimated that a further rise of six or eight feet would precipitate a vast flood of waters over the state of Illinois, from the south end of Michigan; the great Canadian Lakes then discharging also into the Mexican Gulf.--_Brande's Journal._ * * * * * _The Cuckoo_ Has done more for our music than musicians may be willing to allow; but it is no more than justice to a despised bird to say, that from it we have derived the minor scale, whose origin has puzzled so many; the cuckoo's couplet being the minor third sung downwards.--_Mag. Nat. Hist._ * * * * * _Immense Fir-tree._ In the Museum of Natural History at Strasburg, is shown the trunk of a silver fir-tree, from the forest of Hochwald, at Barr, in Alsatia. The tree was 150 feet high, with a trunk perfectly straight and free from branches to the height of 50 feet, after which it was forked with the one shoot 100 feet long, and the other somewhat shorter. The diameter of the trunk at the surface of the ground was 8 feet; estimated age 350 years.--_Ibid._ * * * * * _The Weather by Frogs._