• Zinc and brass are merely separated well enough on the galvanic series to generate voltages (25 June, p 47).
• Logged off: the wood found offshore at Cleethorpes is better described as being preserved by immersion (23 July, p 12).
• Tanja Masson-Zwaan is an assistant professor at the International Institute of Air and Space Law at Leiden University (9 July, p 32).
