THE WOMBAT. 53 



and the whole melted and well mixed at a temperature of 

 about 120 F. One and one-third ounces of absolute alcohol 

 is then added in a fine stream, stirring constantly in the mean- 

 time, and the batch made up to 20 ounces (if not that already) 

 by the addition of distilled water. 



It is then again allowed to set, a convenient vessel for this 

 purpose being a clean jug, and in this condition may be kept 

 some days before using. 



It must be particularly noted that all the operations, after 

 adding the nitrate of silver, must be carried on in a non-active 

 light, and care must be taken when storing to tie up securely, 

 otherwise fogged plates will result. 



The glass to be coated is well cleaned by soaking first in a 

 strong soda solution, then well washing and rubbing under 

 the tap, then soaking again in an acid bath, again scrubbing 

 under the tap, and then placing in racks to dry in a spot free 

 from dust. 



When ready to coat, heat a sufficient quantity of the emul- 

 sion, filter into a small teapot, have the glass warm so as to 

 ensure the regular flow of the solution, and pour on enough to 

 allow of a small quantity being poured off again at each of 

 the four corners ; the proper amount to leave on cannot be 

 well explained ; experience will teach the operator, suffice it 

 to say, that a thick coating is not necessary. When the glass 

 is evenly covered place it on a cold slab of glass or marble 

 accurately levelled, and by the time three or four plates are 

 so treated the first will have set sufficiently to be taken up 

 and placed in a rack in the drying box, where it should be 

 dry and ready for removal in 24 hours. 



{From London, and late with 

 McBean & Son, Melbourne.) 



A. E. BRATLEY, 



Practical Chronometer, "Watch & Clock Maker, Jeweller, Optician, 

 and Silversmith, 



407 1 M&gmbQQi St, t B* QeelQm* a©ar B&twm Brfflgg, 



Watch Work a specialty. All kinds of Horological Work done on the Premises. 



A Twelve Mouths guarantee given for all Watch and Clock Work. 



