THE ST. JOHN'S RIVER, FLORIDA. 217 



" Owing to chemical changes, it is impossible to state the original thickness of 

 the plate, but it is decidedly thinner than its companion. Variations in thickness 

 are evident in different fragments, but taken as a whole they represent a sheet of 

 remarkable uniformity. 



"At certain points, during the process of working, the plate had been beaten 

 or ground through, and here an interesting feature presents itself. To render the 

 plate fit for use it was necessary of course thoroughly to repair such a defect. 

 Accordingly the margin of the opening was worked to a fine edge, against the sur- 

 face of the plate was then applied a thin sheet of copper of size sufficient to cover 

 the hole, and copper rivets were driven through from "25 to '5 of an inch apart to 

 hold it firmly in place. The rivets were placed not only along the margin of the 

 patch but through the body also to fix solidly the superimposed portion of the plate. 

 The task was finished by pressing the margin of the hole as closely as possible 

 against the patch beneath, and by working off the rivet ends projecting on that 

 surface. The delicacy of the work may be judged by the fact that even at the 

 present clay, after long exposure to the action of the elements, it requires the 

 closest scrutiny, after cleaning the surface with acid, to determine the location of 

 the rivets and the line of repair. This of course refers to the exposed surface of 

 the plate, the rivets and patch being clearly evident on the opposite side. The 

 patch was not cut to fit closely the part repaired but extends well beyond, and 

 presents a rough, irregular, unworked margin as though the piece had been ham- 

 mered from a small lump of metal. 



" That this work was done before the completion of the plate, and not to repair 

 holes made during subsequent use, is shown by the way in which the patches par- 

 ticipate in the decoration. 



" But this process was resorted to not only for the repair of such defects, but 

 for the extension of the sheet as well. Along one side of the plate a strip over an 

 inch wide and several inches long has been attached by riveting along the inner 

 edge while the marginal portion has been turned upon itself and closely pressed 

 against the other surface. 



" The posterior plate, about twice as thick as its companion, is from 1 to T5 

 mm. in thickness ; weighs 15 ounces avoirdupois, and, thanks to its greater strength, 

 is comparatively well preserved. 



" The decoration, shown in the frontispiece of this report, is remarkable for 

 the symmetry of the work. It consists of a central perforation 1 surrounded by 

 seven concentric circles, while the space between the outermost circle and each 

 corner is occupied by an hour-glass arrangement of bars with five parallel bars upon 

 one side (Fig. 77). 



"Certain irregularities, however, are evident. The central elevation {M) of the 

 figure in the lower right hand corner is oblong, while the corresponding portion of 

 the other figures is square in outline. The first bar to the left of M is much nar- 

 rower than the others. The inner half of the hour-glass in the upper figures is 



1 Omitted in the illustration. 



