The bestseller that started the non-fiction-as-detective-story trend. It tells of the quest by the 18th-century mechanical genius, John Harrison, to create the ultimate seaworthy timepiece.

THE READERS Carlene Alexander is head of learning support and special needs co-ordinator at Hatch End High School, Middlesex Mark finnemore teaches maths at Coombe Girls secondary school, Middlesex Adam Creen teaches maths at a Sussex secondary school Martyn Potter is a data management specialist in Berkshire Christine Glenis is a primary consultant, teacher trainer and OFSTED team inspector in Kent CA Rivals and enemies abound as Harrison seeks to design the clock that will make it possible for sailors to measure longitude. As much about the history of clock-making, the importance of Greenwich and perseverance as the quest to uncover the secret of mapping. If you enjoyed Fermat’s Last Theorem this is worth a read although it does lack the depth of that book.

MF Sobel has chosen to write a populist account of the life of John Harrison rather than a scholarly text and her book is all the better for it. An easy book to read, Longitude still also informs its reader while laying out the various problems Harrison faced in finding longitude. The story of his 40-year struggle against the sea, Parliament and various astrologers is truly inspiring and may just be enough to help a teacher face a Monday morning.

AC Very much written as a David against Goliath story. Characters are heroes or villains with no middle ground. Historians will dislike the wild jumping about in time, while scientists might want more detail and definitely more pictures. The general reader, however, will find it a short but compelling book that captures the mood of science at the time and puts it in a wider geographic and political context.

MP An account as beautifully and faithfully assembled as John Harrison’s incredible timepieces. Pure science takes a back seat as Sobel builds her narrative on a framework of heroes, villains, political intrigue and loyal devotion. Twentieth-century minds will struggle to comprehend the depth of Harrison’s determination in this tale of astounding achievement against all odds. Mortal characters come and go, but the real stars are Harrison’s seagoing clocks.

CG After a few attempts I was drawn into the tale of Harrison’s lengthy endeavour. It has intrigue, villainy, loyalty, scientific revolution and royal intervention. Sobel writes well using language poetically and scientifically to interweave disappointment and success in this historical context.

Next week: ‘Elizabeth the Queen’ by Alison Weir (Pimlico pound;8.99)