646 PROCEEDINGS OF SECTION H. 



built localities, and 150yds. in more sparsely built ones. Even the 

 shorter of these distances would render necessary the use of a con- 

 siderable length of hose and consequent loss of pressure, and I would 

 urge that a spacing of not more than three chains would be much more 

 effective. By using Sin. hose in lieu of 2|in. the velocity of the water 

 would be reduced below 7ft. per second, and the hose resistance practi- 

 cally halved, whilst the connections (which necessarily pass inside 

 the hose) could also be enlarged from 2Jin. to 2|in., and thus even 

 greater reduction of resistance could be effected. 



The fireplugs next demand attention. These should have the 

 following qualities : — 



(a) They should be prominently marked so that they may easily 



be found when wanted even in dark nights. 



(b) They should be arranged so that the hydrants and hose may 



be quickly and conveniently connected to same. 



(c) They should be of such construction that under no circum- 



stances can the water supply be polluted through street 

 drainage getting access to it through the plugs, more especi- 

 ally when the pressure drops or the water is turned off. 



(d) They should be of such construction as to provide an ample 



waterway for discharge of the water, and hence have small 

 resistance. 



(e) They should be arranged so that the hydrant seat and lugs 



shall not be liable to be obstructed by debris, mud, or rub- 

 bish after rain, &c. 



(/) The cost of the plugs fixed complete in position should not be 

 excessive. 



In cold climates another consideration comes in, namely, the plug 

 and its attachments should not be liable to be blocked or choked with 

 ice. In such cases it is necessary that the water mains and fireplugs 

 be kept below the frost-line, and that provision be made for draining 

 away all waste water which may have collected in the plug chamber, 

 unless the plug be kept warmed artificially during cold weather. Hence 

 fireplugs suitable for use in Australia are not necessarily suitable for 

 Canada or the northern portions of the United States. 



Taking Australian practice, the fireplugs in common use may be 

 divided into two groups, one being that in which the closing is effected 

 by downward pressure, which may be termed the screw-down group, 

 and the other those in which the closing is effected by the upward 

 pressure of the valve — usually a ball — against its seat. Each of these 

 groups may be divided into two sub-groups, namely, those in which the 

 plugs are placed below the level of the footpath or roadway, and are 

 covered by a suitable cover — usually of cast iron — with a movable 

 lid, and the other in which they are placed above the hvel of the road- 

 way or footpath and usually on the line of kerb, so as to form a dwarf 

 post or pillar. The former may be termed roadway fireplugs, and the 

 latter pillar fireplugs. 



All roadway fireplugs are necessarily open to the objections that 

 being placed below the street surface the)^ are necessarily more difficult 



