| Bismuth | 5 |
| Lead | 3 |
| Tin | 2 |
A metallic-glass solder:—
| Lead | 30 |
| Tin | 20 |
| Bismuth | 25 |
The lead is first carefully melted, then the tin added, and the melted mixture carefully stirred; the bismuth is put in last of all.
Cement for iron stoves:—
| Wood-ashes | 10 |
| Clay | 10 |
| Calcined lime | 4 |
To be mixed with water to form a firm paste. Also applicable to holes in trees. Clay mixed with waste-paper is also applicable for the latter purpose (Lehner). (Glue may be added to it.) This mixture of clay and paper should be well mixed with sour milk.
Claus’s cement for metal and glass:—40 grammes of starch and 320 grammes purified chalk are dissolved in 2 quarts water, into which is stirred ½ pint solution of caustic soda.
The most important part of mending broken metal-work is soldering, and this is so difficult to practically teach by mere writing, while it can be so easily learned from any tinsmith, or even tinker, that I deem it common-sensibly best to acquire it from the latter. Those who would study it in all its details, scientific or technological, may do so in Das Löthen und die Bearbeitung der Metalle, by Edmund Schlosser; Vienna, A. Hartleben, price 3s.