Scientific Agriculture. 



140 



[August, 1908. 



per annum, which yield about 325 tons 

 of calcium nitrate. The factory, there- 

 fore, turns out approximately one thou- 

 sand tons of fertilizer per year, but 

 another plant of twenty times this capa- 

 city is soon to be erected. Licenses for 

 the Birkeland and Eyde process are 

 granted by the Aktieselskabet Notod- 

 den Salpeterfabric, Christiania, Sweden. 

 Many plants are at work in Europe on 

 the manufacture of calcium nitrate by 

 this patent, although Norway is more 

 forward in this respect than other coun- 

 tries. At Rjukanfos, a factory is being 

 constructed where 250,000 h.p., is avail- 

 able from water power. 



In the Birkeland and Eyde process, also, 

 a great improvement has lately been 

 introduced by which the percenage of 

 nitrogen is increased and the hygroscopic 

 properties of the product is reduced. 



In the Hawaiian Islands there is with- 

 out doubt a splendid opportunity for 

 the manufacture of either calcium cya- 

 namide or calcium nitrate. The enor- 

 mous and growing quantity of fertilizers 

 required by the cane fields, the anti- 

 cipated reduction of the output of natu- 

 ral nitrogenous compounds, and many 

 other circumstances hold out to the 

 manufacturer of the new products a 

 most promising investment. The avail- 

 able water supply of the Kauai moun- 

 tains naturally would suggest that island 

 as the most appropriate site for such an 

 enterprise, although there are without 

 doubt throughout the islands other 

 available sources of water power. In 

 the near future we predict the introduc- 

 tion to the Hawaiian Islands of one of 

 the processes briefly described, and we 

 hope that such an undertaking will be 

 prosecuted with Hawaiian capital. 



The following letter from the United 

 States Department of Agriculture was 

 recently elicited in response to a request 

 by a correspondent in the Islands who 

 desired information on this subject :— 

 United States Dept. of Agriculture, 

 Office of Experiment Stations, 

 Washington, D.C., March 26th, 1908. 



Dear Sib,— Your letter of February 

 29, asking information regarding the 

 manufacture and use of calcium nitrate 

 and calcium cyanamide, has been re- 

 ferred to this office for reply, 



The Department has not yet inves- 

 tigated the fertilizing value of these 

 materials, but from the large number of 

 reports of foreign investigations which 

 have been reviewed in this office, it seems 

 safe to say that the basic calcium nitrate 

 prepared by the Birkeland and Eyde 

 process is a very valuable fertilizer, 

 fully equal, and in some cases superior, 



to nitrate of soda, particularly on soils 

 benefited by lime as well as nitrate. 

 The results of investigations with regard 

 to calcium cyauamide or lime nitrogen 

 are, however, not so conclusive. There 

 are certain facts relating to the pro- 

 perties and changes which this material 

 undergoes in the soil which have not yet 

 been thoroughly investigated, but which 

 have an important bearing upon its 

 fertilizing value. As far as 1 can learn 

 neither of the products is yet upon the 

 market as staple fertilizing materials. 

 The processes of manufacture, I believe, 

 aie all fully covered by patents both in 

 this country and abroad, but exact in- 

 formation on this point can only be 

 obtained by applying to the U. S. Com- 

 missioner of Patents. 



Very truly yours, 

 A. C. TRUE, 

 Director. 



— Hawaiian Forester and Agriculturist. 

 Vol. V., No 4, April, 1908. 



SMALL IRRIGATION AREAS. 



By W. R. Pry, 

 Fruit Inspector, formerly Manager, Moore 

 Irrigation Farm. 



The recent copious rainfall throughout 

 the State has relieved farmers and stock- 

 owners of much immediate anxiety and 

 labour. It is to be hoped, however, that 

 the experiences in the coastal areas will 

 not be forgotten, but that ensilage- 

 making and provisiou for irrigation 

 will receive more attention. 



It is somewhat surprising that more 

 irrigation has not been practised in 

 many places where running streams 

 occur. Certainly the water in permanent 

 streams cannot always be utilised by 

 settlers without infringing on the ripa- 

 rian rights of others. However, when a 

 stream rises in a farmer's paddock and 

 merely creates a swampy patch — from 

 which most of the water is lost by eva- 

 poration,— the owner or occupier could 

 justly and profitably irrigate a few acres 

 by gravitation. In streams with suffi- 

 cient fall, part of the water could often 

 be diverted by means of an automatic 

 hydraulic ram. These rams are compara- 

 tively cheap (from £3 upwards accord- 

 ing to size), and will effectively raise a 

 small supply from 30 to 150 feet high, 

 without any cost for fuel or attention. 



Again, suitable spots are frequently 

 seen where a valley could be easily 

 dammed and a few thousand gallons of 

 water impounded, to be gravitated or 

 syphoned on to a cultivation patch as 

 required. 



