English by the architect John James, as The Theory and Practice of Gardening (1712, with a 2nd edition in 1728, and a 3rd edition in 1743, when the English landscape garden, might have seemed to make its formal designs passé.) Dezallier d'Argenville's Théorique in its English version introduced the Ha-ha, the invisible fence, to widespread English practice, although Althorp already had one in 1697. Dezailler d'Argenville Dezailler d'Argenville was called upon to edit or contribute more than 600 entries in the Encyclopédie of Denis Diderot and Jean le Rond d'Alembert, published in parts from 1751. Dezallier d'Argenville's interest in natural history resulted in two treatises, on shells and minerals, L'histoire naturelle éclaircie dans deux de ses parties principales, la lithologie et la conchyliologie. (Paris 1742) La Conchyliologie, ou Traité sur la nature des coquillages 1757 etc. The connoisseurship of shells and their most colourful and fantastic form was a gentleman's occupation and a worthy inclusion in a cabinet de curiosités before it became a science under the Linnaean system of classification. He was elected a Fellow of the Royal Society of London in March 1750. Beyond his success in the fields of gardening and natural history, Dezallier d'Argenville was a print collector. He organised his extensive collection by subject rather than by school, as outlined in the 'Lettre sur le choix et l'arrangement d'un Cabinet curieux…' that he published in the Mercure de France in 1727. Within the 'Lettre', which takes the form of an article, Dezallier d'Argenville describes 'Three volumes containing the clothing and fashion of the different nations of the world', and a further volume documenting costumes from his native France. The sale of Dezallier's property, which took place on 3 March 1766 following his death in 1765, mentions within these volumes a total of 1,600 costume prints from the time of King Charles II until 1730. It also describes 'good prints by le Clerc, Picart, Hollar, Royn de Hoog and several Chinese drawings. All four volumes are now located at the Bibliothèque de l'Arsenal in Paris. Antoine-Nicolas Dezallier d'Argenville His son, Antoine-Nicolas Dezallier d'Argenville (1723–1796), was the anonymous author (M. D***.) of Voyage Pictoresque de Paris; ou Indication de tout ce qu'il y a de plus beau dans cette grande Ville en Peinture, Sculpture, & Architecture, which appeared in Paris in 1749, a connoisseur's guide to the chief artistic and architectural monuments of Paris, with accounts of