49 



in'essure and the pressure niav be promptly raised to any point neces- 

 sary to secure satisfactory results. I do not say that it is the best 

 machine for all purposes; it is a good machine for many purposes. 

 It is suggested that when any community having a considerable num- 

 ber of trees to deal with desires to secure an outfit, it communicate 

 with the Experiment Station and obtain such information as may be 

 needed. 



In every case the nozzle is the most important part of the outfit. 

 There must be sufficient power, but there must also be the nozzle 

 which is capable of throwing a fine spray with enough force to cover 

 a reasonably large surface. Nothing known to the writer is better than 

 the Vermorel nozzle, or some one of the modifications that work on the 

 same principle. 



CI.ASSIFIED I.IST OF SHADE TREES. 



The following list of shade trees, based on that prepared by Mr. B. 

 E. Pernow, chief of division of forestry, TJ. S. department of agri- 

 culture, for the Brooklyn Tree Planting and Pountain Society, is 

 arranged in the order of least susceptibility to insect attack, though 

 none are entirely exempt. It is not intended to suggest that they are 

 the best in the order named, except so far as freedom from insect 

 attack in New Jersey is concerned. Dr. Halsted has kindly marked 

 the list for fungous troubles, and the numbers in parenthesis following 

 the names indicate the order of their freedom from disease, No. (1) 

 indicating the species least affected. 



Tree of Heaven (Tallow tree). Ailanthus glandulosus. (3.) 

 Ginko, or Maiden-hair Tree. Ginhgo hildba. (1.) 

 Sweet Gum. Liquidamber styracifltia. (2.) 

 American Linden. Tilia americana. (7.) 

 European Linden. Tilia vulgaris. (8.) 

 Small-leaved Linden. Tilia microphylla. (9.) 

 Tulip Tree. Liriodendron tulipifera. (6.) 

 Cottonwood Poplar. Populus monilifera. (19.) 

 Horse Chestnut. .SJsculus hippocastanum. (18.) 

 Oriental Plane Tree. Platanvs orientalis. (30.) 

 American Plane Tree. Platanvs occidentalis. (21.) 

 Box Elder. Negundo aceroides. (10.) 



