ccxxviii GENERAL SUMMARY OF SCIENTIFIC AND 



$10,000,000. The work of draining the Zuyder Zee, likewise, is 

 said to be seriously contemplated by the Dutch government. This 

 gigantic undertaking, if ever successfully completed, would reclaim 

 some 500,000 acres of highly fertile land, and provide room for a 

 population of 200,000 persons. 



HEATING AND ILLUMINATION. 



During the past year, although we may not chronicle any substan- 

 tial advance in the practical application of gaseous fuel in the in- 

 dustries and the household, nevertheless the discussions of this most 

 important theme, which have ajDpeared in the several technical jour- 

 nals of prominence here and abroad, indicate that the problem is 

 attracting the earnest attention of metallurgists and others. These 

 discussions centred chiefly about the claims that have been put for- 

 ward by the friends and advocates of the " water-gas process " of 

 Lowe, the eminent value of which, we conceive, only the most pro- 

 gressive savans have fully appreciated. To properly comprehend the 

 intensely practical bearing of this subject, a brief rehearsal of the 

 causes of the enormous wastefulness of the svstems of generatino- 

 heat by means of coal, almost universally in vogue, will be appro- 

 priate. 



The buyer of coal purchases, ab initio^ from ten to fifteen per cent, 

 of non-combustible and useless material, in the form of ash, with 

 every pound of coal ; while, on account of imperfections in the con- 

 struction of furnaces, difficult of remedy under existing circumstan- 

 ces, perhaps as much as five per cent, more of combustible, in the 

 form of dust or partially consumed fragments, passes through the 

 grate unutilized. If even now, with so much waste as just indicated, 

 we could really obtain all the useful effect of the remaining eighty 

 or eighty-five per cent, of combustible, the result would be quite 

 satisfactory ; but such is far from being the case. The gasification 

 of the coal, which is a phenomenon attending its combustion, in- 

 volves the using up of a prodigious quantity of heat, the equivalent 

 of the mechanical work performed by the particles in passing from 

 the solid to the gaseous condition which heat is lost so far as useful 

 effect is concerned being stored up in the gaseous particles insen- 

 sible of thermometric measurement. The furnace gases, passing from 

 the chimney at a temperature sometimes as high as 800 Fahrenheit, 

 and carrying off' with them immense volumes of unconsumed carbon 

 in the form of smoke, is another material source of loss ; and the in- 

 troduction into the furnace of cold air and inert nitrogen, tosrether 

 with the absorption of heat by the furnace itself, and its conduction 

 to surrounding objects and the atmosphere, completes the category 

 of losses. Summing up all these items of loss, the fact that not 

 more than fifteen to twenty per cent, of the thermal equivalent of 

 the coal is obtained in well-constructed furnaces and steam-genera- 



