190 PORTLAND STONE QUARRIES. 



down tight between these wedges are introduced, made of the best 

 Swedish iron and weighing from seven to nine pounds each. After 

 a few blows from sledge hammers the rock cracks along the joint ; 

 occasionally the rock will not start and the trenches will break up ; 

 this is called spurring, and fresh trenches have to be made. 

 Minute shells occur under a thin bed lying on the top of the roach. 

 As soon as the piece is separated from the bed the wedges are 

 driven down, and with the aid of flat pieces of iron it is moved six 

 or eight inches apart ; this is called reaming. Some of these pieces, 

 weighing from 150 to 300 tons, can be moved by seven or eight 

 men only. During the process of moving these large pieces, some 

 of the joints will occasionally separate, and if not it is disjointed by 

 force, it is then turned on its side by the help of a crane. Eefore 

 the introduction of this useful and labour-saving machine it was 

 usual to borrow men from the neighbouring quarries. Huge pieces 

 used to be turned with iron bars and cog-wheel jacks by ten or twelve 

 men, some of whom would heave on the jacks while others 

 took a short nip with the bars. When everything was ready one 

 man would say " Stran all so-o ay-so-ay," when the rest would haul 

 with all their strength as each syllable was uttered. The process 

 is called " hauling the rock down." When in this position the 

 next thing to be done is to detach the roach from the underlying 

 whit bed, to effect which a Y-shaped pit or trench is made at the 

 junction, into which thin pieces of iron from ten to twelve inches 

 long and capable of standing great pressure are introduced. These 

 are then tightened up with wedges ; a few strokes of a sledge hammer 

 will effectually separate it from its associated bed. Eoach varies 

 greatly in different parts of the island both in structure and thickness ; 

 it usually consists of numerous casts of shell. At the Bill the 

 roach is made up of small oyster shells. It makes good material 

 for rough walling, is very porous, and not affected by frost. It is 

 well adapted, too, for sea walls and foundations of buildings. When 

 in large blocks and laid in its natural position it will resist any 

 amount of pressure. The whit bed to which the roach is attached 

 when discovered is set apart for use, and if free from joints large 



