258 W R. HEBBLEWHITE. 



AN AUTOGRAPHIC AIR-FLOW RECORDER. 



By W. R. HEBBLEWHITE, B.E. 



(Communicated by Prof. S. H. Barraclough, b.e., m.m.e.) 

 [With Plate XII.] 



[Read before the Royal Society of N. S. Wales, November 1, 1911.'] 



1. Introductory.— The following paper describes the con- 

 struction and method of working of an instrument devised 

 for autographically recording the quantities of gas passing 

 through any system, before discharging to atmosphere. Its 

 construction was primarily the outcome of a difficulty 

 experienced in connection with research work on the steam 

 condenser plant in the Mechanical Engineering Laboratory 

 at the University of Sydney, in which it was found that an 

 accurate measurement of the air-vapour mixture passing 

 through the condenser was essential. ] In the present 

 design the author has endeavoured to produce an apparatus 

 which combines the essential characteristics of simplicity, 

 accuracy, moderate cost, and suitability for every day use 

 in condensing plant tests. 



2. Principle of Action.— The principle on which the 

 recorder works is as follows: — 



The air (or other gas) to be measured is conducted by a 

 pipe into an inverted cylinder floating on water, and free 

 to move vertically. Escape from this cylinder is by way of 

 holes in its side, the number of the holes above the water 

 level being dependent on the height of the float in the water. 



1 The author is indebted to Mr. H. W. Fry, who had previously been 

 making investigations on the condenser, for the suggestion that it might 

 be possible to modify the Weighton Air Gauge so as to accomplish this 

 purpose, and also for his assistance with the design : see " Steam Con- 

 densing Plant for Cargo Steamers," (Morison) in Cassier's Magazine, 

 Vol. 



