MECHANICS AND USEFUL AfcTS. 93 



of St. Helena, and of the famous " Giant's Causeway." But all 

 efforts to utilize it for the manufacture of glass had proved singu- 

 larly unsuccessful until the invention above referred to. Messrs. 

 Chance, Son, & Co., the celebrated manufacturers of Birmingham, 

 who export great quantities of plate glass to this country, are re- 

 ported to have expended not less than a quarter of a million of 

 dollars, some years ago, for this purpose. It is gratifying to be 

 able to add this important source of wealth to the list of those 

 opened to mankind by American inventive genius, and to record 

 the fact that the Newburgh ( N. Y.) Glass Manufacturing Com- 

 pany, organized to work the ore of that vicinity under this patent, 

 are already successfully turning out quantities of glass ware with 

 the two peculiarities of unequalled toughness and unapproachable 

 cheapness. The artificial glass hitherto produced, requiring some 

 30 per cent, of soda or other oxides as a base, consuming 

 much fuel, and losing much dross, evidently could never be 

 cheapened sufficiently for many of the uses for which it is very 

 desirable. The simplicity of this manufacture direct from the 

 native article, the abundance and accessSbilit} 7 of the material, 

 and the extraordinary tenacity of the product common quart 

 bottles of the Newburgh manufacture may be freely used in 

 driving nails into solid timber without risk to their contents 

 must eventually extend existing applications of glass in a benefi- 

 cent degree, and bring it into many uses from which it has hith- 

 erto been excluded. The native glass in this region, and, in fact, 

 generally, being the silicate of iron, has a dark color, and it is yet 

 to be seen how far it can be whitened, by modification of the base 

 and admixture of other bases, so as to become available for the 

 finer purposes. That common window-glass may be produced at 

 a great reduction of cost seems not to admit of doubt, and this 

 alone involves great improvement in the structure of houses, in, 

 common horticulture, and in many other respects. Scientific 

 American. 



GLASS-CUTTING. 



Cutting Glass under Water with Scissors. In order to insure 

 success, two points must be attended to : first and most important, 

 the glass must be quite level while the scissors are applied ; and 

 second, to avoid risk, it is better to begin the cutting by taking 

 off small pieces at the corners and along the edges, and so reduce 

 the shape gradually to that required, for if any attempt is made 

 to cut the glass all at once to the shape, as we should cut a piece 

 of cardboard, it will most likely break just where it is not wanted. 

 Some kinds of glass cut much better than others ; the softer 

 glasses cut best. The scissors need not be at all sharp, as their 

 action does not depend much upon the state of the edge presented 

 to the glass. When the operation goes on well, the glass breaks 

 away from the scissors in small pieces in a straight line with the 

 blades. This method has often proved very useful in cutting 

 ovals, etc., which would be very expensive if ground cut; and 

 though the edges are not so smooth as may be desired for some 



