Show valuable glass when Is glass worth more than golda when it Is the ense of a micro scope the record 1 in ue of the manufactured article over the raw material 1 probably made by this ve biety of glass which multiplies itself 50 times the front lens of a micro objective costing about 5 weighs no more than about of a gramme hence the value of such lenses to the weight of a kilogramme kilo gramme would be about 3 the cost of mak ing this weight of glass Is three to six cents and thus cheri worked up into the shape of a lens the glass has in creased in value about timea |