(4) 4-6 Illustrated by Wes Lowe. Galat clearly explains the basics of how early navigation worked, the limitations of sailing with just latitude as a marker, and how one man solved the longitude puzzle. Lowe's paintings help set time and place, but human figures are stiff. The complex concepts are best suited for older readers beyond the traditional picture-book age with understanding of math, science, and geography. Timeline.

Reviewer: Maeve Visser Knoth

(1) 4-6 Illustrated by Erik Blegvad. Spare prose outlines John Harrison's forty-year quest to determine longitude on a moving ship. Although the emphasis is on Harrison's doggedness, Borden presents the scientific problem deftly. Blegvad decorates the pages with both general scenes of the times (early eighteenth century) and specific incidents from the narrative. An afterword tells the fates of the principal players.

Reviewer: Betty Carter | Horn Book Magazine Issue: March, 2004

(2) 4-6 Illustrated by Kevin Hawkes. This picture book biography focuses on self-taught obsessive clock maker John Harrison, who, in the 1700s, became fascinated with solving the problem of determining longitude at sea. Lasky carefully distinguishes fact from conjecture yet makes the whole story lively and compelling, as do Hawkes's informative, often humorous, illustrations. Bib.

Reviewer: Susan P. Bloom | Horn Book Magazine Issue: March, 2003

(2) 4-6 Illustrated by Dusan Petricic. The spirit of inventiveness pervades this drama of John Harrison, eighteenth-century maker of clocks and watches, who spent his life building a timepiece accurate enough to determine longitude at sea. The comic art serves a dual purpose: it leavens the scientific weightiness and reinforces the imaginative spirit of Harrison as he struggles for forty years to assemble his creation. Bib., glos., ind.

Reviewer: Susan P. Bloom | Horn Book Magazine Issue: November, 2000