On a Photographic Process. 31 



developer, otherwise the process was exactly similar to 

 Mr. Crooke's. 



Some time since it occurred to me that, as one of the 

 reasons for waxing the papers was to obtain a good surface, 

 and that the paper we now obtain has such an excellent surface, 

 it was quite probable, so far as that particular object was con- 

 cerned, the waxing or paraffining might be dispensed with ; 

 and further, that any necessity for leaving the papers trans- 

 lucent for copying was rather the exception than the rule ; 

 and if it were desirable to copy any, those particular ones 

 could be paraffined at any time, or reduced copies could be 

 obtained by the ordinary Collodion process. I therefore tried 

 paper plain and simple, with results excelling those with 

 paraffin ; every part of the process was shortened con- 

 siderably ; the percentage of defective papers was again 

 greatly lessened, the records are whiter and clearer, and the 

 time and trouble o± the first preparation, which even in 

 the case of paraffin was considerable, is done away with 

 altogether. 



The time occupied in the different processes is here set 

 down, and as in these days ''time is money," the saving is 

 worthy of note. : 



Iodizing. Sensitizing. Developing. 



Wax , . 4 hours. 20 minutes 2^ liours. 



Paraffin . 4 „ 10 „ l| „ 



Plain . . 2 „ ^ ?>. ^0 min. 



Therefore the saving of time by using plain paper instead 

 of waxed, taking into consideration that part of the process 

 can be done by the batch, and others by the single papers only, 

 will be at least SO minutes for each paper, or 10 hours per 

 week. I have here some samples of the different kind of 

 paper before and after using ; also, of the records obtained 

 from the several instruments now in use at the Observatory, 

 The importance of any simplification of the photographic 

 methods used by those engaged in practical and experimental 

 science will I am sure be so fully appreciated by them, that 

 no apology on my part will Ibe necessary for occupying 

 your attention with apparently so trivial a matter. 



