WATER AND THE EA'GIA'EER. 659> 



The formulae usually given in works on engineering to computo 

 the mean velocity of water running m natural channels, are, so far 

 as my experience goes, not well adapted to the conditions that obta'in 

 in Queensland, and I venture to give the following formula as better 

 adapted and simpler than those I refer to : — • 



where " V " equals the mean velocity of the stream in feet per second 



— "E" equals the hvdraulic radius or mean depth of the water in. 



fall 



feet, and '" S"' equals the natural line of the slope, or , 



'■ length 



In the design of railways intended to carry traffic at high speed 

 in undulating or hilly country, too much care cannot be taken in 

 the matter of waterways, so that the responsible engineer should be 

 in the possession of the fullest and most reliable information to. 

 enable him to determine the height at which watei-courses, both 

 large and small, should be crossed, and the sectional area of the 

 various openings. 



Tliere are cases, however, in even country so frequently met 

 witli in Queensland, where it is quite safe, for the small traffic at 

 present available, to dispense with all except absolutely necessary 

 waterways, such as at the crossings of well-defined creeks, rivers, or 

 other Avatei'courses where the drainage of considerable basins is con- 

 centrated within definite banks or limits. Such places, of course, 

 must be bridged, although not necessarily at high level. 



I constructed the railway from Normanton to Croydon (94 miles) 

 on this pirinciple, 1888-91, and, although the line has been open to 

 traffic for nearly twenty years, no accident or derailment has resulted 

 in consequence of the departure from usual engineering practice. 



At the present time I am surveying and designing a similar 

 railway in Central Queensland, where for 30 out of 40 miles I propose 

 to allow storm-water to crols the rails without artificial conduits of 

 any description, but the remaining 10 miles being in undulating 

 country, culverts, proportioned to the areas drained, will be 

 necessary. 



Phenomenal Rainstorms. 



Kainstorms of great intensity and duration are not imcommon 

 in Queensland, and are not confined to any particular district or 

 locality. 



On the 21st January, 1887, 18'305 in. were recorded in Bris- 

 l)aiie. Tliis storm wrecked the railway bridge over the Logan River 

 on the South Coast Railway, as well as several bridge.s on the 

 Killarney Brancli Railway. It also severely tried the capacity of the 

 by-wasli at the Enoggera Reservoir, the water rising almost to the 

 crest of the dam. The sectional area of the by-wash was largely 

 ijicreased in consequence. 



At Cardwell on two occasions in January, 1873, I measui'ed with 

 the official rain gauge more than 14 in. in twelve hours, the total 

 record for the month being 63 in. 



The most remarkable storm of which I have any personal know- 

 ledge fell in the month of February, some eleven or twelve years ago, 

 on the resumed part of Bando station, on the western side of the 



