Features
“Patent Perfidy.”
Ozone and the Sanitology of Odors
The Date of the Glacial Era in Eastern North America
The National Academy of Sciences
Photophonic and Spectrophonic Discoveries
Public Works in New York City
Improvement in the Construction of Fences and Posts
Recent Decisions Relating to Patents
Improvement in Animal Shears
Improvement in Water Elevators
Improved Optometer
Miscellaneous Inventions - May 7, 1881
Manufacture of Real Lace by Machinery
Agricultural Inventions - May 7, 1881
Coffee.--its Uses and Medicinal Qualities
Departments
- Departments
Correspondence - May 7, 1881
Notes and Queries - May 7, 1881
Business and Personal - May 7, 1881
New Books and Publications - May 7, 1881
Index of Inventions - May 7, 1881
