And when dinner-time came, being thirsty, the first thing he did was to take a long pull at his can. He had swallowed half its contents at one draught, before he realised what had happened.
The mystified, horrified expression on his face as he set the can down, was almost ludicrous; to his mates who were all in the secret, it was irresistibly funny.
There was a roar of delighted laughter, and Jim's eyes blazed with anger as he glared at the can he still grasped in his hand.
Yes! It was his own can, and they had taken away his coffee and filled it with beer! He had been basely tricked. He stood there realising it, while the roars of laughter were sobering down into words.
"Ha! Ha! old teetotaller! That's the best fun we ever had!"
"Jolly good coffee! isn't it, Jim? If you could only have seen your own face!"
"Never mind, old chap! You can be a teetotaller again to-morrow."
"I won't!" said Jim angrily, "I did try. Now I don't care what happens."
He gathered up his dinner basket and the can of beer, and stalked away, and a silence fell upon the little group of workmen as they watched him.