THE EOYAL AETILLEIIY INSTITUTION. 
35 
The other point is the question of how far a magazine con¬ 
structed on this principle would retain its fire-resisting qualities. 
It is of course essential to the permanent success of one of these 
magazines that it should not gradually deteriorate, from the 
corrosion of the iron by the vapourising and non-conducting 
materials with which the chambers are filled; and this point has 
occupied my consideration. In reply to my enquiries with regard 
to it, Professor Abel writes to me :—“ If the alum and sawdust are 
introduced in a properly dry state, no destructive action upon the 
cases need be apprehended; if they are damp or moist, an oxidising 
action will certainly be established, but unless the moisture present 
is somewhat considerable, this action will not take place to an 
extent to give rise to rapid destruction of the metal. There ought 
to be no difficulty in guarding against the likelihood of such corro¬ 
sion altogether.” 
Messrs. Milner inform me, in reply to my enquiries whether the 
alum and sawdust are thoroughly dry before being put in the safes: 
.“We purchase the alum with particular care 
that it is perfectly dry, and the sawdust we keep in a dry store for 
a considerable time, and when mixed, the composition is perfectly 
dry.” Messrs. Milner have also furnished me with some par¬ 
ticulars of safes made on this principle which have resisted fire 
successfully at periods of from 20 to 30 years after being manu¬ 
factured. 
I therefore see no reason to doubt the permanent resisting 
qualities of these magazines. 
In conclusion, I desire to express my opinion that the general 
adoption by retail dealers and private consumers of fire-proof 
magazines, of Messrs. Milner 5 s or some other approved construc¬ 
tion, would tend largely to reduce the risks at present existing 
in connection with the storage of powder in houses, shops, ware¬ 
houses, and crowded localities. 
I have the honour to be. 
Sir, 
Your obedient servant, 
Y. D. MAJENDIE, Major R.A. 
The Right Honourable H.M.’s Inspr. of Gunpr. Works, 
The Secretary of State, 
Home Department, 
Whitehall . 
As to the per¬ 
manently relia¬ 
ble character of 
Milner’s maga¬ 
zines. 
Conclusion. 
