196 Royal Society of Victoria. 



address the meeting, said that being a stranger in Victoria, he 

 was diffident in speaking to the question, and regretted that he 

 had not heard Mr. Steane's paper in full. A formula for the run 

 off of flood waters would be of great value. To apply it to 

 different classes of soil would be difficult ; their absorbent qualities 

 might, however, be tested. The average and maximum rainfall 

 should be ascertained ; when the soil was saturated, the run off 

 would be greater. In India, there are large numbers of rain 

 gauges, but not enough for satisfactory results. The police are 

 found the most reliable persons to have charge of them. The 

 gauges should be exactly alike, and the same height from the 

 ground. It towns where the absorption was at a minimum, about 

 80 per cent, of the run off was generally provided for. 



Mr. Ellery said it was certain, though unexplained, that 

 gauges registered more the nearer the ground, irrespective of 

 splash, for it decreased up to 30 feet, although not so much in dry 

 seasons. 



Mr. White thought the subject could scarcely be treated 

 scientifically. If a formula were found applicable now, it may 

 not be so in say 20 years, as physical and atmospherical conditions 

 change, and the removal of forests would produce a difference. 



Mr. Jennings said the methods of measuring the discharge of 

 rivers was very defective. It was recently proposed to divert the 

 main river at Rangoon. He took the discharge with floats, and 

 with electric gauges, and at various depths he found great differ- 

 ences. He thought the electric gauges were the best, as they 

 could be applied at any part of the section of the river. 



Mr. Ellery thought the method employed here was very 

 imperfect ; obstructions and friction had to be taken into account. 



Mr. Steane described the method used by him. 



The President said the discussion illustrated well the peculiar 

 position of engineers. They have to estimate on wretchedly 

 inadequate data, for the expenditure of millions. He had to leap 

 in the dark and hope for the best. Superfluous millions are spent 

 on some bridges and culverts, and yet occasionally an accident 

 like that at Cootamundra occurs. Men of experience in South- 

 east Australia allow 40 square feet to the square mile of catchment, 

 and they appear to be about right. But some formula is urgently 

 required, and it is to be hoped that Mr. Steane will continue 

 his important work of collecting data. A law can only be deduced 

 from an abundance of facts. 



Baron von Mueller's " Description of some Papuan Plants," 

 was accepted as read, being purely technical. (See Transactions, 

 Articles XYII. and XYIII.) 



A paper " On the Production of the Tides Mechanically 

 Considered," by Mr. T. Wakelin, B.A., of Greytown, N.Z., was 

 ^■hen read by the President. (See Transactions, Art. XIX.) 



