Page:The Steam Turbine.djvu/27

 The diagrams on page 11 show the latest method of forming segments of blades by stringing blades and distance pieces alternately on wire within a groove formed of two castings bolted together and corresponding to the groove of the turbine rotor or casing. The engraving on page 12 illustrates these segments being made. The view on page 15 shows segments being fitted in a rotor.

I have said that steam behaves almost like an incompressible fluid in each turbine of the series, but because of its elasticity its volume gradually increases with the succession of small falls of pressure, and the succeeding turbines consequently are made larger and larger. This enlargement is secured in three ways: (1) by increasing the height of blade, (2) by increasing the diameter of the succeeding drums, and (3) by altering the angles and openings between the blades. All three methods are generally adopted (page 17) to accommodate the expanding volume of the steam which in a condensing turbine reaches one hundredfold or more