The two most eminent practitioners of the period, however, active during the middle of the century, were Johann Georg von Langen and his pupil, Hans Dietrich von Zanthier, both of noble family, and better educated than most of their contemporaries, and both engaged in the organization and management of Harz mountain forests, namely, those of the Duke of Brunswick and of the Count of Stolberg-Wernigerode.
The former, without occupying himself directly with literary work, laid down in his expert reports and in his working plans many instructions which form the basis for orderly management and silviculture far ahead of the times. Zanthier, writing considerably (especially Kurzer systematischer Grundriss der praktischen Forstwissenschaft, 1764), is also notable as the founder of the first forestry school (at Wernigerode), 1763.
Another of this class of better educated practitioners, and co-worker with the former two, was von Lassberg, who in 1764-1777 organized the Saxon forests.
An interesting incident in the life of the last three men is their journey to Denmark and Norway, whither they were called to organize the management of the forests connected with the mines.
Another prominent forest manager of the last half of the century, whose literary work is to be found only in various excellent official instructions, among which is one for the teaching of foresters, was the head of the Hessian forest service, a nobleman, v. Berlepsch.
Of the cameralists who helped to make forestry literature, six or seven deserve mention. These, men of education and polyhistors, were either at the head of affairs, or else professors at universities, where they included forestry as one of the branches of political economy.
The credit of the first really systematic presentation of forestry principles and rules, as developed at the time, belongs to Wilhelm Gottfried von Moser, a pupil of von Langen, who served in various principalities, and finally with the Prince of Taxis. In his Principles of Forest Economy, published in 1757, which for the first time brought out the economic importance of the subject, he discusses in two volumes divided into nine chapters the different branches of forestry.
A mining engineer, J. A. Cramer, came next with a very notable book, “Anleitung zum Forstwesen” (1766), which, although not as comprehensive as Moser’s, treats the subject of silviculture very well.
Equal in arrogance and opinionated self-satisfaction to any of the empiricists with whom he frequently crossed swords, was the Brunswick councillor, von Brocke, who, as an amateur, practising forestry on his own estate, developed the characteristic trait of the empiricists, namely, a profound belief in his own infallibility. He produced, besides many polemic writings, in which he charged the whole class of foresters with ignorance, laziness and dishonesty, a magnum opus in four volumes, entitled “True bases of the physical and experimental general science of forestry,” which is an olla podrida of small value.
Less original, but more fair and well informed, a typical representative of the cameralists, was J. F. Stahl, finally head of the forest administration of Württemberg, and at the same time lecturer on mathematics, natural history and forestry at the forest school of Solitude (Stuttgart). Although an amateur in the field of forestry, he was a good teacher and left many valuable and wise prescriptions evolved during his administration.