ILLUSTRATIONS. 



PLATES. 



Page. 



Plate I. Method of covering small tree with bell or hoop tent 16 



II. Fig. 1. — Brick furnace, tank, and derrick used in the tannin 

 treatment for mildew, San Bernardino County, Cal. Fig. 



2. — Machine for covering trees with sheet tents 20 



III. Fig. 1. — Method of attaching tent to hoisting pole by a' half hitch 

 of the rope. Fig. 2. — Top of derrick, showing method of 

 attaching pulley. Fig. 3. — Base of derrick, showing method 



of constructing braces 22 



IV. Fig. 1. — Supply cart used with the improved system of fumiga- 

 tion. Fig. 2. — Supply wagon devised by C. E. McFadden 



of Fullerton, Cal 22 



V. Figs. 1-5. — Successive stages in placing a tent over a tree with 

 poles. Fig. 6. — A tented tree, showing method of securing 

 the distance around the bottom of the tent by means of a tape 



attached to an iron rod 26 



VI. Removing the tent from one tree onto another by means of poles.. 26 



VII. Placing a sheet tent over a tree by means of derricks 28 



VIII. Fig. 1. — A row of tented trees, with cart at one end of row, ready 



to commence dosing. Fig. 2. — Dosing a tree 38 



TEXT FIGURES. 



Fig. 1. Map showing principal localities in southern California where citrus 



fruits are produced 7 



2. Plan for construction of octagonal sheet tent 50 feet across, showing 



lines used in constructing octagon 14 



3. Method of attaching hooks to tent when covering trees -with aid of 



derricks 16 



4. Ends of hoisting poles used in placing tents over trees 20 



5. Earthenware acid jar with attachments for field use 23 



6. Carboy with handles attached to facilitate pouring the acid and carry- 



ing the carboy 26 



7. Outline of a sheet fumigation tent marked according to the Morrill 



method 29 



8. Man carrying tray and water bucket as practiced under the old system 



of fumigation 31 



9. Dosage schedule No. 1, for potassium cyanid 34 



10. Chart showing total amount of gas evolved when different proportions 



of water are used 45 



11. Dosage schedule No. f , for potassium cyanid 59 



12. A cover device attached to a fumigation generator 75 



IX 



