Swords need iron.

For finding iron, small boys are ideal.

On the beach, in the depths of winter, these small boys were finding and collecting rocks and bringing them back to the growing pile. The best rocks were small, about the size of a thumb, and deep rust-red. They dropped them at the feet of the waiting overseer. The overseer then ran a metal rod over the stone and added it to the pile or tossed it away before dispatching the boys to search for more.            

It’s a common fate for children born to archaeologists. They get put to work on archaeological projects – such as finding ironstone to smelt down into iron. The rod was a magnet; if the rock stuck, it had enough iron to make it worth the keeping.