

3 



JOHNSON & ROBINS' 



OFFICE 



OF CONSULTING ENGINEERS, 



AND COUNSELLORS FOR PATENTEES: 



For imparting information on the subject of Inventions, and on the application of 



Chemical and Mechanical Science to the Arts, Agriculture, Manufac- 

 tures, and Mines, and for procuring and defending 



Patents, either in the United States or 



in foreign countries. 



Prof. Walter R. Johnson, late of Philadelphia, and Z. C. 

 Robbins, of Washington City, (to be aided by Hazard 

 Knowles, Esq., late Machinist of the United States Patent Of- 

 fice,) have associated themselves together for the prosecution of 

 the above branches of professional business, either in their office, 

 at the Patent Office, or before the courts ; and will devote their 

 undivided attention to forwarding the interests of Inventors or 

 others who may consult them, or place business in their hands. 

 i The office of Messrs. J. & R. is on P street, opposite the Patent 



~ ~ where communications, post-paid, 

 will be promptly attended to; examinations made, drawings, spe- 

 cifications, and all requisite papers prepared, and models procured 

 when desired, on reasonable terms. Letters of inquiry, expected 

 to be answered after examinations made, must be accompanied 

 by a fee of five dollars. 



Office, Washington, D. C, 



Washington, D. C, June 1, 1848. 



[Nov. 1848.— ly] 





