Proceedings, &c, for 1885. 171 



This formula will not hold in all cases ; for example, if 

 a = -f -acre 



'-Tooo 



r = 3 in. per hour 



(so that D must be less than |- cubic feet per sec.) 



the formula gives 



o x 



D = 3 X *75 ^/8 = 5-3 cubic feet per sec, 



i 

 and this result is obviously false. 



It will thus be seen in how very unsatisfactory a state is this 

 branch of engineering. Some attention should certainly be paid 

 to it, and one may safely say that in a few years we shall be in a 

 better position than at the present time. 



30th September, 1885. 

 The Cootamundka Railway Disaster. Professor Kehnot 



The details of this fearful disaster are fresh in the memory of 

 all our members. A heavy flood washed away a portion of the 

 railway embankment near Cootamundra, N.S.W., and a train 

 dashed at full speed into the chasm. Many people were killed^ 

 and more injured. — 25th January, 1885. 



His acquaintance with the site was formed during two journeys 

 in a slow train shortly after the accident. Cootamundra is about 

 half-way between Wodonga and Sydney. It is situated in the 

 Murrumbidgee watershed. The Dividing Range is crossed about 

 100 miles further on towards Sydney, so that Cootamundra is not 

 on the rainy-coast watershed, but is characterised by a climate 

 more like that of Victoria. The portion of the bank which was 

 washed away is at the crossing of the Soft Clay Creek. This 

 creek is a tributary of the Murrumbidgee, and flows through 

 country very much like that about the Yarra at Kew. The line 

 crosses the creek by three culverts — (1) an 8-ft. barrel drain, 

 equal to 52 square feet; (2) apparently the same; (3) a brick 

 barrel drain, having about 200 square feet of waterway. The 

 country is lightly timbered, and the formation is hard rock to the 

 surface, apparently stratified. There was heavy rain on the 24th 

 January, and a small breach was formed at the third culvert ;. 

 another was formed at the second, and the accident took place at 

 the first. The catchment area is variously stated at from 20 to 30 

 square miles. Mr. Whitton say3 13,000 acres. - 



For the defence Mr. Morell, of the New South Wales Railway 

 Department, stated that one- third of the area was not very 

 absorbent, and that the rest consists of flats and uncleared ground. 



