TOLKE POLLUTION OF WATERS BY FACTORY REFUSE. 623 



be about 30,000 mark =$7,140. This sum would be distributed as fol- 

 lows: 



For pipes - $4,700 00 



For steam-pump 952 00 



For draining and grading 20 hectares 1, 428 00 



7, 140 00 



Subtract from this 5 per cent, interest, 2 per cent, amortiza- 

 tion = 7 per cent, per annum 8476 00 



Eent of 20 hectares, at $42.84 per hectare 850 80 



Cutting the grass 285 00 



Eepairs 285 GO 



Superintendence 238 00 



Total per annum 2, 142 00 



Value of harvest, at $172.50 per hectare 3, 450 00 



Netgain ... 1,308 00 



In making this calculation we have not taken into account the great 

 advantage of having a large quantity of good hay, which is much needed 

 in all sugar factories. The manufacturer, who is generally a farmer, can 

 give his cattle larger quantities of better hay than hitherto ; the cattle 

 will enjoy better health, and he will have more animal manure, thus 

 saving the expense for artificial fertilizers. Those factories which are 

 worked by a joint-stock company could then give a meadow-area to each 

 one of the stockholders in proportion to the amount of stock held by 

 them. 



The well-known civil engineer, A. Elsasser, formerly of Loburg, now 

 of Magdeburg, has most successfully introduced a filtering apparatus 

 for the refuse water in the sugar factory at Eoitsch (province of Sax- 

 ony), and any one interested in this question may there convince himself 

 that the water becomes perfectly clear and odorless. The apparatus at 

 Eoitsch, however, is too small, and with the same amount of water twice 

 the area could be irrigated. 



Mr. Elsasser wants, for successful irrigation, a very level ground with 

 tolerably loose soil, so the fluid parts of the manure may be evenly dis- 

 tributed. The area which is to be irrigated should be drained at the depth 

 of about one meter; the drain-pipes should lie close together, and be so ar- 

 ranged that the water may flow off easily. The chemical substances con- 

 tained in the refuse water should penetrate the soil only to a compartively 

 small depth, in order to let the further disintegration take place under 

 the cover of the soil, so that the nutritious matter which has assumed a 

 gaseous form may be assimilated by the soil, and thus find its way into 

 the roots of plants. In this manner the soil is always ready to receive 



