The reverse side of the postcard reads: "DJ Thanks very much for PPC. Glad to hear you arrived home all save. I am feeling the effects of the granite too. Nellie." It is postmarked March 3, 1910 from Aberdeen. I presume PPC is "Picture Post Card," though most frequently people have been shortening it to PC. But that last line is a bit of a question mark for me. I can only speculate, but I have to think that Jack had gone to Aberdeen (the Granite City) to visit Nellie and perhaps they had gone to the quarry? Or if someone from the area has a better explanation, I'd love to hear it.
Jack was still in Scotland at this time, but preparing to head to Canada. A visit (or several) to his fiancé would make sense.
I hadn't really thought of it before, but Jack and Nellie hung onto these postcards for a reason (or two). My Great-Uncle Jim, the last time I saw him, told me that they used to have these postcards in a big album on the coffee table in the living room - their own picture book. I'm sure they were wonderful visual reminders of the home they had left forever, but also of that sweet time in a couple's existence: courtship.