Helmholtz Resonators
These "universal resonators" were likely purchased  for 380 Fcs. in 1896 ($300.99 then, almost $7,000 in 2005 dollars) through the James G. Biddle Co. from Rudloph Koenig of  Paris, France (information on the previous link is from the 1889 Catalog) .
.
.
.

 

Back

Back to Topical IndexBack to Maker Index    Back to Device Index    Back to Date Index