Mr Fairbairn on Fireproof Varehouses. 109 
Fifthly, That the iron coloumns, beams and brick arches, 
be of strength sufficient not only to support a continuous dead 
pressure, but to resist the force of impact to which they may 
be subject, by the falling of heavy goods upon the floors. 
This is one of the most important considerations connected 
with the security and construction of warehouses ; and in or- 
der to remove every doubt as to the stability of such a struc- 
ture, I must refer to my highly-talented and respected friend, 
Eaton Hodgkinson, Esq., F.R.S., one of the first authorities 
in this or any other country on the strength of materials. 
To that gentleman the public are indebted for a series of 
theoretical and practical experiments on the strength of 
beams and pillars, of the utmost value to architects, builders, 
and engineers. Any person choosing to make himself ac- 
quainted with the principles of Mr Hodgkinson’s experi- 
ments, and the results deduced therefrom, will find no diffi- 
culty in constructing beams and columns of the strongest 
form, and at the same time insuring the proportional and re- 
quisite strength, accompanied with a great saving in mate- 
rial in all parts of the structure. On this part of the subject 
it will be necessary to observe, first, on the structure of 
beams, that until the publication of Mr Hodgkinson’s expe- 
riments, practical men were almost entirely without rule, or 
any satisfactory theory on which to found their calculations 
on the form and distribution of the material. Now the sub- 
ject is well understood, not only as regards the strength 
which is wanted, but also the best and strongest form for re- 
sisting the different strains to which they are subjected. In 
warehouses containing goods, these strains are more varied 
than in factories. In the former, the floors are often loaded 
to a great extent with solid dense material ; at other times 
with light bales ; and the lower floors are frequently piled 
with casks containing mineral substances, which produce not 
only a great amount of dead pressure upon the beams, but 
incur the risk of some of the heavier weights falling from 
some height upon the floor, and thus endangering the secu- 
rity of the structure by the fracture of the beam. These ac- 
cidents are probably not frequent, but they should be guarded 
against ; and the beams, arches, and columns should not only 
