| LOCKYER | Norman -, founder of scientific journal Nature jointly credited with detecting helium in 1868 (7) |
| WYKEHAM | William of -; bishop who directed the reconstruction of the upper ward of Windsor Castle in 31 Any one of the 300 billion luminous bodies of hydrogen and helium in the Milky Way whose birth takes plac |
| IMPEACH | To charge with offences, as in the case of US President Andrew Johnson in 1868 (7) |
| RAGTIME | King Of ____ , nickname of U.S. composer and pianist Scott Joplin born in 1868 (7) |
| WEATHER | Helium in water changing climate (7) |
| METLIFE | US insurance company founded in 1868; I'm fleet (anag.) (7) |
| CORNING | City in Steuben County, New York, to which the Brooklyn Flint Glass Works moved in 1868 and adopted its name |
| TABASCO | Popular hot pepper sauce created by Edmund McIlhenny in 1868 |
| DANRICE | Circus clown who ran for president in 1868 |
| ITALICS | Type of scientific old language briefly resurrected (7) |
| OLOGIES | Podcast that focuses on a different branch of scientific study each episode |
| HUNTER | Type of pocket watch with a hinged lid; a brand of wellington boot; or, Scottish anatomist considered a founder of scientific surgery (6) |
| NATURE | Scientific journal in which the existence of neutrons was first proposed |
| STAR | Any one of the 300 billion luminous bodies of hydrogen and helium in the Milky Way whose birth takes place inside a nebula (4) |
| LEIBNITZ | Wilhelm ____ is jointly credited for the discovery of calculus |
| BIOSPHERE | New-fangled probe is filled with helium in a controlled environment (9) |
| NATUREABHORSAHOOVER | Reason that the prestigious scientific journal refuses articles from President Herbert's relatives? |
| SMITHFIELD | Meat and poultry market in London which opened in its modern form in 1868 (10) |
| REAL | Old unit of currency in Spain, replaced by the peseta in 1868 (4) |
| BRAZIL | Angela, writer of 'modern schoolgirls' stories', born in Preston in 1868 (6) |
