LAYING OUT THE DESIGN OF WORKS. 45 



Another common defect is inadequate and bad designing 

 between the hydraulic main and the holder inlets, and the 

 absence of a foul main. The result of this is trouble in the 

 winter and in cold weather. The gas pipes may be taken 

 direct into the open air by a short cut through the retort 

 house wall, passed into a condenser, and thence to a small 

 set of purifiers. Under such conditions we may confidently 

 anticipate trouble from accumulations of pitchy matter, 

 which clog the seal boxes, and bays back the condensed 

 liquid, preventing it from getting away to the store well. 

 A large quantity of tar and liquor goes forward into the 

 purifier connections, necessitating stoppage for clearance 

 at frequent intervals, and increasing the back pressure, 

 while the purifying material, being called upon to complete 

 the extraction of tar, in addition to discharging its own 

 legitimate function of removing carbonic acid and sulphur- 

 etted hydrogen, becomes clogged and inactive long before 

 it is properly saturated in a chemical sense. A chemical 

 examination of the spent lime heap will show the presence 

 of a very appreciable proportion of free or unused lime, or, 

 if oxide is used, the oxide will be rejected as spent and 

 inactive before it has accumulated a proper proportion of 

 free sulphur. I have seen samples of so-called spent oxide 

 that contained less than 40 per cent, of free sulphur, and 

 were really inactive because they were clogged with tar. 

 The extravagant consumption of material, increased working 

 expenses and incidental loss will increase the manufacturing 

 costs to an extent much larger than is required to pay 

 the interest on the cost of a properly designed plant. If a 

 lad of ten is dressed in his father's old clothing, shortened 

 in the sleeves and legs, the result is not satisfactory, either 

 from a utilitarian or aesthetic point of view. This fairly 

 represents the position at some small works, where the 



