his frame arrangement (Bienen-Zeitung, May 1852) following Dzierżon's discovery that grooves added to inner walls remained free of propolis (1848). Thus, the correct distance between frame side-bar and hive wall was already understood by some European beekeepers before 1851. Langstroth's patent of 5 October 1852 adopted −the upper limit of the bee space, slightly larger than optimal− between the side bars of a frame and hive wall, and also reserved rights to use the distance between top-bars and inner cover, the latter of which represents a gap larger than optimal. The term 'bee space' was coined later than Langstroth's 1852 patent. Langstroth had been aware of Dzierżon's discoveries before he submitted his patent application. In the summer of 1851, he was introduced to Dzierżon's work by Samuel Wagner, who had visited Dzierżon in his apiaries in Silesia and subscribed to , the journal in which Dzierżon published his apiarian works, and who had translated from the German language original (though the translation was never published). Langstroth expressed great respect for Jan Dzierżon, saying that "No words can express the absorbing interest with which I devoured this work. I recognized at once its author as the Great Master of modern apiculture". Design The original Langstroth hive had a portico entrance, integrated floor and non-removable brood box, a single removable honey box (using the same frame size as the brood box) that sat inside an outer box that extended from the brood box, and a hinged roof. Langstroth constructed his hives so that the frames, in which the bees were to make their combs, could easily be separated from all adjacent parts of the hive — the walls of the hive, the floor of the hive, the cover of the hive, and other frames within the hive. To extract a frame from such a hive will not require any comb to be cut. Usually the most trouble a beekeeper encounters in removing a frame from such a hive results from the bees using propolis to bond frames to the brackets they rest upon. Being able to remove and replace combs so easily makes it possible, and practical, for beekeepers to inspect all of their hives on a regular basis. Such inspections, to check for signs of disease and/or parasites, imminent swarming, an aging queen, and other conditions requiring intervention, are essential to successful bee husbandry. The Langstroth bee hive is made up