INFLUENCE OF WEATHER ON ACIDS IN RAINFALL. 89 



the laboratory equipment previously used by Anderson has been added 

 to, provision having been made for the simultaneous evaporation of 

 sixteen samples of water in a specially designed electrically heated 

 water-bath. The methods employed are those used in the previous 

 research, and which are described in a recent number of the ' Quarterly 

 Journal of the Eoyal Meteorological Society. ' 



During the period between September 1914 and March 1915 the 

 activities of the Committee were confined chiefly to organisation, includ- 

 ing the establishment and equipment of collecting stations, and involving 

 a considerable amount of correspondence with observers and others. 

 On March 15, however, the preliminary arrangements were sufficiently 

 far advanced to permit of samples being collected regularly at all 

 stations, and since that date the scientific work of the Committee has 

 been carried on uninterruptedly. In order that the seasonal variations 

 might be studied, and that the results may be of real value, samples 

 should be collected and examined from all stations until March 1916. 



During the progress of the experimental work the results, as soon 

 as they are completed, will be correlated with the meteorological data. 

 In this aspect of the work it will be necessary to draw largely upon the 

 publications of the Meteorological Bureau, particularly in regard to the 

 daily isobaric charts of Australia. The observers are provided with 

 forms for the purpose of making notes of the weather conditions on 

 days when rain is recorded. Sample forms, together with other forms 

 used in tabulating the results, are appended (Appendix B). 



Up to the present time no work has been done by the Committee 

 upon the direct determination of the amount of nitrogen peroxide in the 

 atmosphere. The difficulties connected with this work are very con- 

 siderable owing to the exceedingly small proportion of this gas normally 

 present in air. _ However, it is thought that these difficulties may be 

 overcome, and it is the intention of the Committee to proceed with this 

 phase of the work as soon as possible. Additional apparatus will be 

 required for this purpose. 



A list of apparatus in the possession of the Committee is appended 

 (Appendix C). 



This Interim Report is submitted with the request that the Committee 

 be reappointed with a further grant of 20Z., for the purpose of carrying 

 on the investigation outlined in the foregoing pages. 



APPENDIX A. 



' Ithaca,' 



Victoria Avenue, 



Canterbury. Vic. : 



n c- Feb. 17, 1915. 



Dear Sir, ' 



The following are enclosed for use in connection with the work of the 

 Kesearch Committee on Nitrogen Acids in Rain.-water :— 



1. A descriptive list of the apparatus supplied ; 



2. A list of general instructions ; 



3. A list of the names and addresses of the Observers who are co-operatinc with 



the Kesearch Committee; 



4. A map showing the approximate positions of the observing stations : 



5. A drawing showing the method of setting up the collecting gauge; 



