I was 19 and working my way through college in Southern Illinois and worked at a lumber yard for over 2 years.
The worst job I had was to unload a full boxcar of various length and width boards. I "rode the forks"(of the fork truck)up to the top of the load, which was only 3' from the top of the inside of the car and was, in Summer, around a furnace in temp. Each board had to be passed out to the waiting forks, and then sorted by length and width on the ground. It took two of us 10-14 days to do a car.
But, I was 19 and not 14. I made $1.40/hr, and at least back then one could still work their way through college.
And, I had mostly much better jobs at the yard, like waiting on customers and then driving delivery.
Regardless, I tip my hat to that tough little 14 y/o. I hope he found other opportunities in this industry along the way.

Re: Groovy wheels

Those look like standard wheels to me. The shadows are falling in such a way as to seem like flanges over the track. (Notice where the boy's shadow is.) That plus the usual lensatic effects of these large format cameras. The wheel on the rightmost cart is easier to judge by.

The wheelsets have outside flanges. Isn't this kind of unusual or are the wheels double flanged (grooved)?

To put this into some sort of perspective this 14 year old was paid $1 a day. Presumably he's working a full day, because that's what kids did in those days. And that that day wasn't your namby pamby eight hour day in a forty hour work week. it was more than likely a twelve hour day or more. So what rivlax's $24 today (actually according to the US Bureau of Labor Statistics says it's $23.27) is pretty close to $2 an hour. Or to convert it back to the wages of the time (because the kid wasn't getting modern wages he was getting wages of the period) the kid is getting paid $.083 and hour. Yes just a fraction over 8 CENTS an hour. Not good for anyone at any time.

My late father used to tell the story about his days as a teenager working in a sawmill in the hot Florida woods before he got drafted into WW2. "Pulling slabs" was the hardest most miserable job he ever had before or since. At the time he was on his high school football team and was 6 feet and 210 pounds and a pretty tough guy (he thought). But that job broke him and he quit after a week. He said he was actually glad to see the letter from Uncle Sam.

$1 a day sounds terrible to modern ears, but it had considerable buying power at the turn of the last century. My CPI calculator only goes back to 1913, and even then $1 had the buying power of $24 today, so in 1903 it was probably a few dollars more. Not bad for a kid in those times.