When the gorilla became known to science

The discovery of a skull found in 1846 by a missionary in the French Congo was the first available evidence of the existence of a gorilla. About five years later, the Royal College of Surgeons acquired the first complete skeleton ever brought to Europe.

Then in 1858, the British Museum procured (obtained) the first complete skin.

However, unknown to zoologists, a gorilla was actually alive in England even in 1855. It had been brought from West Africa by a travelling menagerie (collection of wild animals on exhibition).

The owners had been under the impression that it was a chimpanzee and discovered it was a gorilla when its skin and skeleton were examined after its death.

The first account of the gorilla, that of Andrew Battle who lived in West Africa around 1590, appeared in Purchas' Pilgrimage (1613) He called it a "pongo".

Which gem was named after a prince

The alexandrite was named after Alexander II of Russia because it was discovered in 1833 in the Ural Mountains of Russia on the very day on which the majority of that monarch, then heir to the thrown was being celebrated.

It is a mineral which crystallises into six-sided crystals and possesses the quality of being dark green when seen in daylight but light red when seen by artificial light.

The discovery seemed a welcome coincidence because the colours of the military of imperial Russia were also red and green.

Why the sky is blue

The rays of the sun are scattered by the countless tiny specks that fill the air, when striking the Earth's atmosphere.

The blue rays are scattered further than the red so we see the blue more than the other colours. If the air were free of all particles of dust, the sky would be quite dark and be relieved only by the brightness of the Sun, Moon and the stars which would always be visible.

What menhirs, cromlechs, dolmens and sarsens are

The first three of these terms are used by archaeologists to identify various kinds of megalithic (large stone) erections dating usually from prehistoric times intended for religious or other purposes.

A menhir is a single upright stone, which is sometimes huge and was erected to mark a grave boundary or as a sign of victory.

A cromlech is strictly an enclosure, generally circular, composed of separate standing stones. Stonehenge is known as a cromlech though it is not a typical one.

A dolmen is a sepulchral burial chamber composed of a number of upright stones roofed with a single large capstone. In England, the term cromlech was formally used instead of dolmen for sepulchral chambers.

A sarsen or greyweather is an isolated block or hard sandstone which has been left behind after erosion. Sarsens are common in southern England.