3 86 



better. It, therefore, never should be used immediately after 

 cutting up. The chief points in the foregoing directions are the 

 quantities given must be taken exactly. Lye poured into the grease, 

 not grease into the lye. The lye and liquid grease must be well 

 stirred until the mixture is complete and uniform, but not longer. 

 The mould containing the soap must be well wrapped up. The 

 soap, after cutting up, must be kept for a time. The grease used 

 must not contain any salt, which would completely prevent the 

 soap from forming. Australasian Fanner. 



SOLDERING. Soldering is very useful for joining copper and 

 copper, copper and brass, copper and iron, brass and brass, brass 

 and iron, tin and tin, and tin and any other metal. If the joint has 

 to stand a rather high degree of heat, such, for instance, as the 

 seams of a small copper steam boiler, a hard solder must be used. 

 By hard solder is meant one that only fuses at a high temperature ; 

 a soft solder, on the contrary, fuses at a low degree of heat. The 

 following are the compositions of some of the most useful of 

 solders and alloys, with the degrees of heat required to melt 

 each : 



Tin. Lead. Bismuth. Mercury. Melts at 



1 part 25 parts 558 Fahr. 



2 parts i part 340 



3 2 parts i part 2920 

 5 3 3 parts 2O2 

 5 it 3 3 3 Parts i22 



We must see with \vhat tools and appliances soldering is 

 effected, and the way in which this operation is performed. First, 

 the surfaces to be united must be thoroughly cleaned and 

 brightened ; without this the metal will not adhere. The solder- 

 ing iron must be warmed sufficiently to melt the solder ; it must 

 not be made red-hot, because the solder will not " hold to it." 

 Whilst the iron is warming, tin the surfaces by brushing them 

 over with muriatic acid, dipping them into the melted solder, and 

 quickly nibbing off the adherent metal. This, if clone well, will 

 leave a thin coat of solder. When it cannot be done thus, the sur- 

 faces must be tinned by means of the soldering iron. In this case 

 they must be coated or washed with the acid as before, but the 

 solder must be melted on the places required with the hot iron. 

 When tinned, the surfaces must be brought close together, a little 

 aeid rubbed along the joints, and the iron dipped in the acid and 

 put against some solder, so that the melted solder will stick to the 

 iron The iron must now be applied to the joints, and drawn 

 slowly along in such a manner that the metal between the joints is 

 melted, and the joints filled up. A little practice will soon make 

 the amateur tolerably skilful in doing this. The muriatic acid, or 

 spirit of salt, as it is sometimes called, must be killed, or rendered 

 neutral, before it is used, and this is clone by putting one or two 



