1884.] Determination of Pressures of Granular Substances, 225 



January 31, 1884. 

 THE PRESIDENT in the Chair. 



The Presents received were laid on the table, and thanks ordered 

 for them. 



Pursuant to notice Anton De Bary, Carl Gegenbaur, Leopold 

 Kronecker, Rudolph Yirchow, and Gustav Wiedemann were severally 

 balloted for and elected Foreign Members of the Society. 



The following Papers were read : — 



I. "Determination of the Vertical and Lateral Pressures of 

 Granular Substances." By Isaac Roberts, F.G.S., F.R.A.S. 

 Communicated by J. F. Bateman, F.R.S. Received 

 November b\ 1885. 



Paet I. — Wheat and Peas. 



The investigations which I have the honour to submit in this com- 

 munication have been undertaken to furnish data to engineers and 

 others who are concerned with the erection of structures which have 

 to sustain pressure upon floors and retaining walls, and also to further 

 the objects of science in a field that is believed to be new. 



Store-houses have been erected, both in this country and in America, 

 which consist of rectangular cells, called bins, and are filled with 

 grain to a height of 50 feet and upwards above the ground. 



Diligent inquiries have been made for any scientific data or rules 

 by which the necessary strength of the walls and floors of such 

 structures could be computed, or, for instance, what would be the 

 vertical and lateral pressure of a column, say of wheat, 14 feet square 

 at its base and top, and 60 feet in height. It was generally assumed 

 to be something less than the pressure of a similar column of water, 

 but how much less did not appear to be known either in England or 

 America. 



Last year I made experiments to obtain data, by employing models 

 of square and hexagonal bins, particulars of which were communi- 

 cated in a paper read in Section Or, at the meeting of the British 

 Association for the Advancement of Science, held at Southampton. 

 I give briefly, in tabular form, the results. 



