The eight-pointed white cross on a red background is instantly recognisable as the logo of the Order of St John. The origins of this charitable organisation, which oversees the St John Ambulance organisation worldwide, go back to a knightly order known as the Order of Knights of the Hospital of St John of Jerusalem. The courage in adversity shown by the ‘Hospitallers’, as the Order’s members were known, is symbolic of fortitude, the pillar of knighthood to which the fourth coin in the Knights’ Tales series is dedicated.

Given just how tough the armoured ankylosaurus magniventris was, it is not surprising that this massive herbivore was one of the last large non-avian dinosaurs to roam the earth. Looking like a four-legged tank with a broad torso covered in humps, spines and protected by a bone-plated corset, not to mention horns pointing backwards from the back of its head, ankylosaurus magniventris is brought to life in vivid detail on the fourth coloured coin in the Supersaurs series.

Faster than Sound, the fourth and final coin in the Reaching for the Sky series, is dedicated to the undisputed star of commercial air travel, the supersonic airliner Concorde. The most iconic and glamorous airliner to ever grace the skies, Concorde was not only a triumph of engineering but, with its delta-wings and slightly bent nose, also a design classic. In service from 1976 to 2003, Concorde captured the public imagination like no other civil aircraft before or since.

The Internet creates infinite possibilities and gives instant explanations by placing the world at our fingertips. But while surfing the net we leave visible traces that businesses use to learn about our individual preferences by analysing the resulting large data sets, meaning that users lose their privacy and autonomy. Big Data, the latest edition in the best-selling Silver Niobium series, highlights the dangers and disadvantages of the digital revolution.