INVASION, the entry into a country by a public enemy. As as 1795 Congress pro vided by law for protection against the invasion of the United States by any foreign nation or Indian tribe. The act made it lawful whenever there should be an invasion, or imminent dan ger- of one, for the President to call out such number of the militia of the State or States convenient to the place of invasion as he might think necessary to repel it. This, strengthened in some respects by amendments, has been in force ever since. An invasion has usually all the elements of war, and the invaders may be dealt with as persons at war with the country invaded, in accordance with usages of warfare without the declaration of war by Congress. The Supreme Court of the United States has decided that a State is invaded when there is a domestic rebellion within its territory, and that the same rules of law may be enforced as in the case of an invasion by external foes. This de cision practically abolishes all distinction be tween invasion and insurrection, and the same rules which furnish a remedy for invasion can be applied in the suppression of an insurrection or local rebellion. In case the State militia is not sufficiently strong, or not easily available, the standing troops of the United States may be ordered out by the President, if indeed it be necessary to call upon the State troops before resorting to the regular troops of the United States. It is not necessary that actual armed violence shall be resorted to in order to consti tute insurrection. Any combination of persons too powerful to be suppressed by the ordinary course of judicial proceedings is tantamount to insurrection, and warrants the use of the effec tive measures provided for by law for its sup pression.
As regards the rights of the invader many rules have been laid down, carefully distinguish ing between invasion and conquest, especially with respect to private and public property. It
is now held that public money, military stores and public buildings with their contents are lawful sources of plunder, and telegraph and railway property may be used as needs require. The unwarranted burning of the Capitol and other public buildings in Washington by the British in 1814; the removal of the Palatine libraries during the Thirty Years' War; the confiscation of the astronomical instruments in the Observatory of Peking by the Germans dur ing the operations of the Allies against the Chi nese capital — all these were in direct violation of the accepted rules of invasion. The levying of supplies, labor, forage, transportation facili ties, etc., upon the native people is strictly within the lawful confines of invasion • for example, during the wars of Frederick the Great, both the Austrians and the Prussians were mainly supported by these enforced contributions of supplies. Napoleon was probably the greatest exponent of the belief that a war should sup port itself, either during the conflict, or by im posing a large indemnity, or both; hence we see that he exacted of Prussia, after the battle of Jena, more than a hundred million francs, and Spain was forced during the Peninsular War to pay a similar amount. The pillage of private property is prohibited, but should the owners give aid to their country, the property may be sold at the discretion of the invading general. INVENTION OF THE CROSS, a festi val held in honor of the finding of the true cross, on which Christ was crucified, by the Em press Helena A.D. 316, on Mount Calvary, cele brated on 3 May. Since 1895 the festival is called °Ritrovamente as celebrating the re finding of the cross, which was identified and buried in the 1st century by Empress Protonice.
See CROSS.