A word like ""revolution"" comes in for a lot of misuse these days. For Mr. Tyler -- Assistant President of the International Ladies' Garment Workers' Union and Director of their Department of Politics, Education, and Training -- it is little more than a four-syllable synonym for any sort of change. ""Trade Unions in a New America"" is the subtitle here, and no aspect of labor organization, past or present, that is incompatible with trade unionism is included in this account. Nevertheless it is an interesting and quite rewarding book, dealing as it does with the new areas now becoming or yet to be organized. The trend today is away from blue-collared industrial wage-earners to salaried professionals and members of the service trades; geographically it is aimed at the South and Southwest, rather than labor's old strongholds, the North, Midwest, and Pacific Coast. Two problems Mr. Tyler treats at considerable length, intriguingly if not quite conclusively, are ""The Challenge of Automation"" and ""The New Negro."" Another subject of a ticklish nature, handled with a good deal more finesse, is the double-barrelled one of labor in politics and vice-versa.