Welding Cast-Steel.
| Rock saltpeter 1/4 | pound. |
| Oil vitriol 1/4 | pound. |
| Water1 | gallon. |
Dissolve the saltpeter in the vitriol and add it to the water. After scarfing the steel get it hot; and quench in the preparation. Then weld the same as a piece of iron, hammering it very quickly with light blows. It answers the purpose much better than borax. Cork it in a bottle and it will keep for years.
Another:
| Borax15 | parts. |
| Sal-ammoniac2 | parts. |
| Cyanide of potassium2 | parts. |
Dissolve all in water, and evaporate the water at a low temperature.
To Drill Hardened Steel.
Cover your steel with melted beeswax, and when cold make a hole in the wax with a fine-pointed needle or other article the size of the hole you require; put a drop of strong nitric acid upon it, and after an hour rinse off and apply again. It will gradually eat through.
To Drill Holes in Cast-Iron.
By means of carbolic acid a hole 1/4 of an inch in diameter has been drilled through 1/2 inch thickness of cast-iron with a carpenter’s brace.