486 KANSAS CITY REVIEW OF SCIENCE, 
All of the desiderata are united in lime. It is a powerful base, it is very 
abundant and cheap ; its glass is much more fusible than iron, and is also so much 
lighter that it floats freely on top of the melted iron, and thus niay be run off 
through an overflow conduit or tqp hole. Lime, therefore, is used, but it must 
not be used at random for the following reasons : If the supply of lime is not 
sufficient to combine with the silica, this will unite with the oxide of iron and 
form a wasteful iron glass, or its silicon will remain excessively in combinaUon 
with the iron itself. If, on the other hand, the lime is in excess, we may get 
into trouble, due to the fact that uncombined lime is a most refractory substance, 
practically infusible, as proved by its use in the lime-light where a mixture of 
oxygen and hydrogen gases in vivid combustion strikes against a cylinder of 
lime, making it so intensely white-hot that the light it emits is the most brilliant 
obtainable. This oxy-hydrogen is hotter than any furnace yet constructed. 
Cinder or Slag. — This explanation of the rationale of fluxing in the blast 
furnace explains also the composition of the cinder (so often misnamed "slag," 
as we shall explain hereafter), which carries away everything excepting the pig 
iron and the gases. It is mainly a lime glass, and, being a glass, a multitude of 
schemes have been devised and patented for using it as a material for bottles 
and for other purposes to which glass is applied. The inventors have not suffi- 
ciently considered the fact that lime glass is much more iriable than lead glass, 
or soda glass, or potash glass, or the mixtures of these that form the material for 
our windows, bottles, etc. 
The problem of utilizing this mixture of silicates in which silicate of lime 
variably preponderates is not yet solved, on a scale commensurate with the sup- 
ply of the material. It still remains a worse than worthless waste product, as its 
disposal is costly, partly on account of its bulk and weight in carriage, and partly 
on account of the ground it covers and renders useless. Of all waste products 
of British manufactures this one is about the most unmanageable. — Iron. 
ARCHEOLOGY. 
THE LAKE DWELLERS OF VENEZUELA. 
In many parts of the world, particularly In Europe, there are remains of the 
structures of an ancient people known as Lake Dwellers, from the fact that they 
lived in houses built over the water. In that beautiful sheet of water in Switzer- 
land, Lake Geneva, there are such remains, but there are savage tribes in Oce- 
anica who illustrate the ancient practice to-day, dwelling in huts built upon poles, 
at a considerable distance from land. In America the only instance of this mode 
of house building is found in the lake of Maracaibo, which lies in the north of 
Venezuela. Whether or not this habit of living suspended above the water is 
