206 DISCUSSION ON TWO PRECEDING PAPERS. 
Mr. CHARLES P. WETHERBEE, Member:—There is one feature in connection 
with the low-pressure turbine, in combination with the reciprocating engine, that 
I do not think has been brought out in connection with Mr. Anderson’s paper. 
The steam is at such low-pressure in the steam belt of the low-pressure turbine that, 
the ordinary type of axial dummies or what you might call contact dummies that 
is used in Parsons turbine need not be employed, and the radial type of dummies, 
such as is usually used, with the astern cylinders, can be employed with a very small 
loss of economy. : 
Furthermore, the tip clearance of the blades, which has been criticised in some 
cases in the past, can be greatly increased without any serious loss of economy. 
The radial dummy feature permits the use of a turbine that does not require any 
accurate means of obtaining the fore and aft position of the rotor, with reference to 
the cylinder, and does not require any accurate thrust adjustment, for the reason 
that this dummy will permit great longitudinal motion of the rotor without any 
damage. 
These two things together overcome in this low-pressure turbine the criticisms 
that have been made of fine clearances in the Parsons turbine, and furthermore, a 
thrust-block can be used on this turbine that does not have the thrust on one-half 
of the collars only. The top and bottom halves can both be used with a thrust-block 
of the ordinary type, because the amount of float allowed in the thrust-block used 
with reciprocating engines is not sufficient to permit the rotor to touch any part 
of the cylinder. These are of very great advantage. 
Mr. W. L. R. Emmet, Member.—In connection with the subject of the use of 
reciprocating engines with turbines, I want to call attention to a method which I 
proposed in connection with the battleships Wyoming and Arkansas, which I think 
can be easily proved to be far better than the methods which are shown in Mr. 
Anderson’s paper and can be put in practice on many ships. I do not advocate this 
method which I then advocated, because I have since proposed a better one; but if 
people must use reciprocating engines with turbines, I think that the proper way 
to do it is to exhaust the reciprocating engine into a high-speed turbine. Let that 
high-speed turbine drive a generator and put the power back on to the reciprocating 
engine shaft with a motor. There would be absolutely nothing problematical or 
peculiar about this. “The turbine machinery has to do no reversing, it has to per- 
form no functions that are not generally performed by turbines and generators and 
motors everywhere, and it conduces to a very much better efficiency of the turbine, 
because the turbine can run at the speed which is most desirable. It receives the 
steam from the reciprocating engine at any desired pressure, any proportion of the 
total work of the steam can be put upon the shafts by this method, and the system 
is perfectly flexible. 
For some unaccountable reason the shipbuilders of the world and the naval 
architects of the world seem to have decided to ignore electric propulsion of vessels. 
Being used to seeing new things commercially adopted when their merits could be 
demonstrated promptly, this is a strange condition to me. 
