Mr. Lens, a veteran unionist, follows up his history of Working Men (and a cursory first chapter recap) with a knowing examination of unions themselves at work, especially in collective bargaining and handling interim grievances. Here is a plausible set of demands for a new contract, analyzed in categories (union security, job security, money benefits, fringe benefits), spelled out in terms of specific cases. Enforcement of the contract and establishment of precedents also commands attention close up: can a worker be labeled ""accident-prone"" if his employer has failed to install safety devices? is it insubordination to refuse to work on an unfamiliar machine? Other sections describe how workers are organized from the inside and (more commonly) from the outside; the structure of the labor movement by trade or industry, and by area; the chronology of a strike (including methods of sustaining morale); off-the-job union services; lobbying and political action. Mr. Lens takes note of occasional racketeering and corruption, of the decline in identification that accompanies rising living standards, of controversy over officials' salaries and racial discrimination; he is less than incisive on the latter, ignores the problems of white collar and professional and civil service unionization, and barely alludes to the drift of organized labor from the vanguard to the rear guard of social reform. But as the only close study of prevailing practices, it should be exceedingly useful.