Misc: Which British scientist invented a safety lamp for miners?

Questions

What reduction is indicated when a measurement is prefixd by the word pico?

What disaster hit Ireland between 1845 & 1849?

Who are Yum-Yum and Nanki-Poo?

Who is Jeeves' young master?

What was Much Binding in the Marsh before it became a country club and then a radio show?