308 BULLETIN OF THE BUREAU OF FISHERIES. 
patents which have been granted to me by the governments of Australia, Ceylon, 
India, Japan, and other pearl-producing countries, or countries which have 
pearl-producing colonies and dependencies. 
DESCRIPTION OF INVENTION AND CLAIMS AS PATENTED. 
The object of this invention is (1) to provide means for taking radiographs 
or of making fluoroscopic examinations of separate pieces of matter or objects in 
considerable quantities, so that they may be taken simultaneously for the pur- 
pose of making radiographic examination of these objects and pieces of matter, 
and then (2) readily to identify each radiograph as being that of the particular 
object or piece of which it is the representation. 
The manner of taking radiographs at present is to make exposures of indi- 
vidual objects placed upon photographic plates, or other sensitive radiographic 
media, either in direct contact or with the plate properly inclosed in paper to 
keep out light. The exposures having been made, by means of the X rays, 
Ro6ntgen rays, or any other rays penetrating matter opaque to light, the object 
is removed from the plate or other sensitive medium and set aside, the sensitive 
medium being then developed through ordinary photographic process and 
examined. 
This method is cumbersome and expensive, and precludes the radiographic 
examination of many different materials. Also it can not be utilized in connec- 
tion with large bodies or numbers of objects for commercial purposes. My 
particular aim in connection with the present invention is the ascertaining of 
the presence of pearls of any size or form in pearl oysters (Margaritifera vulgaris) 
without injury to the oysters; but the invention is not limited with respect to 
the character of the objects under examination, as it may be used for any objects 
whatever. Ordinary processes and apparatus could not be used for this pur- 
pose, for the reason that they would be too cumbersome, slow and expensive, 
and entirely unsuited. 
For the purpose of examining the material quickly and cheaply, I utilize a 
tray or conveyer of considerable surface, over which the material may be spread 
or carried, and this tray or conveyer is then laid upon the sensitized radiographic 
medium. ‘The latter is of a size larger in area than the tray or carrier itself, the 
excess being sufficient to allow for the distortion due to the rays falling upon the 
outer area at a considerable angle. 
The exposure having been made, the tray is lifted from the sensitized 
medium, or in the event of the conveyer it is so adjusted as to be carried beyond 
the sensitized medium. ‘The latter is then developed, and the resultant radio- 
graph, which is the full size of the tray, except for the increase in size due to the 
distortion, can be compared to the objects or material on the tray itself, these 
objects or material not having been disturbed, and occupying at this time the 
same relative position as in the particular radiograph on the sensitized medium. 
