DIKES OF THE NETHERLANDS. 
335 
known to the inhabitants of the Netherlands at the time of the 
Koman invasion, and the elder Pliny’s description of the mode 
of life along the coast which has now been long diked in, 
applies precisely to the habits of the people who live on the 
low islands and mainland flats lying outside of the chain of 
dikes, and wholly unprotected by embankments of any sort. 
It has been conjectured, and not without probability, that 
the causeways built by the Romans across the marshes of the 
Low Countries, in their campaigns against the Germanic tribes, 
gave the natives the first hint of the utility which might be 
derived from similar constructions applied to a different pur¬ 
pose.* If this is so, it is one of the most interesting among 
the many instances in which the arts and enginery of war have 
been so modified as to be eminently promotive of the blessings 
of peace, thereby in some measure compensating the wrongs 
and sufferings they have inflicted on humanity, f The Low- 
* It has been often asserted by eminent writers that a part of the fens 
in Lincolnshire was reclaimed by sea dikes under the government of the 
Romans. I have found no ancient authority in support of this allegation, 
nor can I refer to any passage in Roman literature in which sea dikes are 
expressly mentioned otherwise than as walls or piers, except that in Pliny 
(Hist. Hat. xxxvi, 24), where it is said that the Tyrrhenian sea was excluded 
from the Lucrine lake by dikes. 
t A friend has recently suggested to me an interesting illustration of 
the applicability of military instrumentalities to pacific art. The sale of 
gunpowder in the United States, he informs me, is smaller since the com¬ 
mencement of the present rebellion than before, because the war has 
caused the suspension of many public and private improvements, in the 
execution of which great quantities of powder were used for blasting. 
It is alleged that the same observation was made in France during the 
Oriinean war, and that, in general, not ten per cent, of the powder manu¬ 
factured on either side of the Atlantic is employed for military purposes. 
It is a fact not creditable to the moral sense of modern civilization, that 
very many of the most important improvements in machinery and the 
working of metals have originated in the necessities of war, and that 
man’s highest ingenuity has been shown, and many of his most remarkable 
triumphs over natural forces achieved, in the contrivance of engines for 
the destruction of his fellow man. The military material employed by the 
first Napoleon has become, in less than two generations, nearly as obsolete 
as the sling and stone of the shepherd, and attack and defence now begin 
