009 
XIV, 6 Dar Juan and Elicano: Philippine Glass Materials 475 
a capacity of from five to ten thousand bottles is to be operated, 
it will be unwise to depend entirely upon unskilled labor. In 
this connection it would be advisable to in- 
vestigate the capacity limits to which ma- 
chine blowers can be operated economically, 
and to draw conclusions from the results of 
this investigation as to whether it would be 
more economical for the present to contract 
expert glass blowers from Japan to train 
Filipino laborers or to operate an automatic 
machine blower. 
As shown by the composition and the qual- 
ity of the glass, there is not the slightest 
doubt that the raw materials are suitable for 
glass making. Furthermore, in order to de- 
termine whether or not they would stand the 
pressure and the sudden changes of temper- 
ature to which glass bottles are subjected in 
a factory under ordinary working conditions, 
a number of glass bottles made by the Bu- 
Fig. 2. Elevation of the experimental glass furnace. Section through ABCD. a, chimney, 
made of galvanized or plain sheet iron 1/16 inch thick. 
165559 2 
