THE LAST COWBOY by Jane Kramer; Harper & Row; 148 pages; $8.95
The plight of the cowboy in the age of computer ranching is a familiar story. Journalist Jane Kramer nevertheless manages to refresh the tale with a selection of tactful though telling observations and details that, with allowances for scenery and idiom, remind one of Jane Austen at Mansfield Park. "Onion was ornery and bucked a lot and enjoyed kicking over the chair that Henry, at six, climbed to mount him. It took a while for them to arrive at the abusive, affectionate arrangement that Henry later claimed was so instructive...