Read the poem given below and answer the questions that follow : Between my finger and my thumb The squat pen rests: snug as a gun. Under my window, a clean rasping sound When the spade sings into gravelly ground. My father, digging. I look down Till his straining rump among the flowerbeds Bends low, comes up twenty years away Stooping in rhythm through potato drills, Where he was digging The coarse boot nestled on the lug, the shaft Against the inside knee was levered firmly. He rooted out tall tops, buried the bright edge deep. To scatter new potatoes that we picked, Loving their cool hardness in our hands. What is the overall tone of the poem ?