FIRE-RESISTING -BUILDINGS. 89 



porous by mixing sawdust with the clay, which was consumed 

 during the firing process. 



Stood 25^ hours" exposure to maximum temperature of 

 2,000" F., and neither fire, water, nor smoke passed through it. 



Xo. 2. — Partition of slabs of pumice, volcanic sand, and 

 Portland cement 21" X n^" X 2^" thick, plastered to make 

 total thickness of 3^/'. 



Stood 2 hours" exposure to maximum temperature of 

 2,000° F.. and neither fire, nor smoke passed through it. 



No 3. — Partition of slabs of plaster of Paris and coke 

 breeze i to i ; 24" X 12" X 2%'', with one-sixteenth wires in 

 joints, and plastered with ^'' of plaster of Paris, and coke dust 

 I to I. 



Stood ijA hours' exposure to maximvmi temperature of 

 2,100° F., and fire did not penetrate it. 



No. 4. — Partition of slabs of pumice, slag sand, hydraulic 

 lime, tan and plaster of Paris, say, 4.0" X n'' X 2^)4", with 

 five-sixteenth iron rods passing through same vertically at 12" 

 centres, and with -)4" plaster on fire side. 



Stood 1% hours' exposure to maximum temperature of 

 1,800° F. 



No. 5. — Partition of slabs of plaster of Paris mixed with 

 cocoa-nut fibre and cork dust and with reeds embedded horizon- 

 tallv. Slabs set in mortar composed of plaster of Paris, lime 

 and sand mixed 2:1:2. Plaster 1 14" (over two sides) thick. 

 Slabs 4' 10'' X 10" X 2y» or finished 3^^". 



Stood il-i hours" exposure to maximum temperature of 

 2,000° F. 



No. 6.— Partition of bricks 133-^" X 7->4" X 3f4" composed 

 of plaster of Paris, hydraulic lime, coke, sand, asbestos and 

 sulphuric acid laid in mortar of hydraulic lime and sand, and 

 plastered with fireclay on fire side, finished thickness 3J^". 



Stood I hour of maximum temperature of 1,800° F. 



No. 7. — A partition of terra-cotta and wired lathing plas- 

 tered three coats both sides to a finished thickness of 23/2", the 

 plaster being of lime, sand, and plaster of Paris. 



Stood three-quarters hour exposure to maximum tempera- 

 ture of 2,000° F. 



Hollozc Partitions. — Partitions plastered both sides with 

 steel or other inflammable lathing have proved to be prac- 

 tically useless when the studs to which the lathing is 

 secured are of untreated timber. If the timber is 



rendered " non - flammable " by the process hereinafter 

 referred to, the result would no doubt be more satis- 

 factory; but, generally speaking, the cost of rendering hollow 

 lathed and plastered partitions effective, even as fire resisters, 

 entails so much labour and material that ii is cheaper and better 

 to adopt the solid partitions. The British Fire Prevention 

 Committee, however, found as follows: — 



