The publication of the Dictionnaire universel of Furetière in 1690 ushered in the age of the encyclopaedic dictionary. This was a relatively short-lived phenomenon of little more than a hundred years, but one which pathed the way to modern encyclopaedias. Furetière having died in 1688, his successor was Basnage de Beauval, a protestant exile based in the United Provinces of the Netherlands. It was Basnage who in the new 1701 edition transformed the dictionary by enlarging it considerably to a more genuine encyclopaedic coverage and calling on specialists to rewrite key sections, notably on the natural sciences. The simile of the hourglass is a means to show how the dictionary mediated knowledge from a vast array of sources and made the data available to contemporary and current day users. This paper demonstrates the hourglass effect through the lexicographical and learned sources that Basnage and his major compiler of scientific data, Regis of Amsterdam, brought into service. It looks at how Regis used numerous botanical sources in writing entries on Brazilian flora. Finally, we examine the influence of the work on the phenomenon of the universal dictionary and the development of the encyclopaedia.