THE JONSON ABSOLUTE FORM QUOTIENT: HOW IT IS 

 USED IN TIMBER ESTIMATING 



By H. R. Wickenden 



The method of determining tree volumes and tree taper by means 

 of the Jonson Absolute Form Quotient and Form Point seems to have 

 aroused a good deal of interest in America. 



The absolute form quotient, volume and taper tables, and the form 

 point method were discovered and worked up by Prof. Tor Jonson of 

 the Royal Technical School of Forestry of Sweden in 1910. 



It was put to actual test in making an enormous strip timber survey 

 of the Province of Varmland in 1912. This estimate covered 7,430 

 square miles. The results obtained were compared to local statistics 

 and figures already available, and those obtained from local lumber 

 companies, and were found to be exact. It was consequently adopted 

 almost exclusively for timber computations by all lumber companies. 

 The simplicity and flexibility of the method was appreciated by Nor- 

 wegian and Danish foresters who soon followed the example of their 

 Swedish confreres.^ 



The very fact that the system has been used almost exclusively in 

 Scandinavia for nearly ten years, and that it has practically put old 

 methods out of use, should convince practical men of its usefulness. 



Having used it in practice, and seen its extensive application in 

 Sweden during my three years' stay in that country, I am very much 

 surprised to find that, although a very good translation of Jonson's 

 articles was published in America some years ago, American timber 

 estimators still overlook this method of measuring timber, not realizing 

 the advantages and simplifications in lumber estimating and stem 

 analysis work. During the ten years following its discovery, despite 

 severe tests, the form point and form quotient still retain the entire 

 confidence of those who made use of it in their practice. 



^ How far the Jonson method has been tried out in other European countries 

 is uncertain. Where reliable local tables of all descriptions are plentiful. 5uch 

 as, for instance, in Germany, it is not surprising that the interest displayed for 

 new methods of timber estimating is not very pronounced. 



