Which Joe gave his name to ‘sloppy joes’? We look at five interesting sandwiches and their lexical origins.
An early reflecting telescope in which light reflected from a concave elliptical secondary mirror passes through a hole in the primary mirror. It was rendered obsolete by the introduction of Newtonian and Cassegrain telescopes.
- ‘Therefore, for certain applications, Gregorian telescopes have desirable advantages over other telescope designs.’
- ‘He subsequently became the most successful London manufacturer of Gregorian telescopes, which were named after their original inventor.’
- ‘Mostly, he made mirrors for Gregorian telescopes, which were compact and produced upright images, suitable for royalty and nobility, who used them to look out their castle windows.’
- ‘There are two different classes of two-mirror telescopes: Cassegrain telescopes and Gregorian telescopes.’
- ‘An off-axis Gregorian telescope with correctly chosen offset angles will always be optically superior to a similar on-axis configuration.’
Mid 18th century: named after James Gregory (1638–75), the Scottish mathematician who invented it.
We take a look at several popular, though confusing, punctuation marks.
From Afghanistan to Zimbabwe, discover surprising and intriguing language facts from around the globe.
The definitions of ‘buddy’ and ‘bro’ in the OED have recently been revised. We explore their history and increase in popularity.