True, young Benjamin's ""eyes fairly danced with excitement,"" but it's contagious: this is an inspirational biography so thoroughly conversant with black aspirations and Maryland history (the author is a black Baltimore librarian) and so attentive to the particulars of its hero's accomplishments as to make him a hero indeed. At six he becomes the proud co-owner of 100 ""Crown Colony of Maryland"" acres. From the Bible (and his grandmother) he learns to read; a Quaker schoolmaster opens up a ""new world"" of mathematics, of ""parts to be added, divided, made larger or smaller, taken apart and put together again."" On Patterson's part, calculated words. The sight of a watch, and its loan, starts him building ""the wonderful wooden clock"" that first makes him famous. Educated neighbors, the Quaker Ellicotts, acquaint him with surveying and astronomy; and, at almost 60, he exchanges most of his farm for a lifelong annuity and time to pursue his new interests. Though the account is dramatized, what is invented is not implausible--and what is crucial or controversial is forthrightly stated. Banneker collaborates with Andrew Ellicott in surveying the land for the new capital city; then, after Pierre L'Enfant is dismissed, the two execute his plans. Did Banneker himself redraw the plans from memory? The evidence is lost, we're informed; sufficient, the ascertainable. But what is most intriguing, and made Banneker still ""more famous,"" is his almanac. From the details of its compilation--complete to original astronomical charts (B. Franklin's were borrowed)--we come to appreciate its significance in demonstrating (as a publisher's foreword noted) ""that the colour of the skin is in no way connected with strength of mind or intellectual powers."" So, BB, ""philomath""--in the most meticulously appreciative young biography yet.