"A couple of days later I got in from a round trip and made a dive for the boarding-house.
"'Any mail for me, mother?' I asked old Mrs. Cameron.
"'No, young man; I'm sorry to say there ain't'.
"'I was anxious to hear from home.'
"'Too bad; but maybe it 'll come to-morrow.'
"I was up to fever heat, but could do nothing but wait. I went to bed late, and, raising up my pillow to put my watch under it, I found a note; it read:
"'Midnight, July 17.
"'Dear Joe:
"'Just thought of that rule for changing counter-balance you wanted. There has always been a miscalculation about the weight of counter-balance; they are universally too heavy. The weights are in pieces; take out two pieces; this treatment would even improve a mule sweep. When once out, pieces should be changed or placed where careless or malicious persons cannot get hold of them and replace them. All is well; hope you are the same; will see you some time soon.
"'Jack.'
"Here was apparently a fool letter from one young railroader to another, but I knew well enough that it was from Rachel and meant something.
"I noticed that it was dated the next night; then I commenced to see, and in a few minutes my instructions were plain. The old five-stamp mill was driven by a mule, who wandered aimlessly around a never-ending circle at the end of a long, wooden sweep; this pole extended past the post of the mill a few feet, and had on the short end a box of stones as a counter-weight. I would find two packages of gold there at midnight of July 17.