[Footnote 305: No siege takes place without the besieged accusing the besiegers of neglecting the rule that buildings devoted to religion, art, charity, the tending of the sick, and the like, must be spared during bombardments. The fact is that in case of a bombardment the destruction of such buildings cannot always be avoided, although the artillery of the besiegers do not intentionally aim at them. That the forces of civilised States intentionally destroy such buildings, I cannot believe.] It must be specially observed that no legal duty exists for the attacking forces to restrict bombardment to fortifications only. On the contrary, destruction of private and public buildings through bombardment has always been and is still considered lawful, as it is one of the means to impress upon the authorities the advisability of surrender. Some writers[306] assert either that bombardment of the town, in contradistinction to the fortifications, is never lawful, or that it is only lawful when bombardment of the fortifications has not resulted in inducing surrender. But this opinion does not represent the actual practice of belligerents, and the Hague Regulations do not adopt it. [Footnote 306: See, for instance, Pillet, pp. 104-107; Bluntschli § 554A; Mérignhac, p. 180. Vattel (III. § 169) does not deny the right to bombard the town, although he does not recommend such bombardment.] X ESPIONAGE AND TREASON Vattel, III. §§ 179-182--Hall, § 188--Westlake, II. pp. 79 and 90--Lawrence, § 199--Phillimore, III. § 96--Halleck, I. pp. 571-575, and in _A.J._ V.(1911), pp. 590-603--Taylor, §§ 490 and 492--Wharton, III. § 347--Moore, VII. § 1132--Bluntschli, §§ 563-564, 628-640--Heffter, § 125--Lueder in Holtzendorff, IV. pp. 461-467--Ullmann, § 176--Bonfils, Nos. 1100-1104--Despagnet, Nos. 537-542--Pradier-Fodéré, VI. Nos. 2762-2768--Rivier, II. pp. 282-284--Nys, III. pp. 256-263--Calvo, IV. §§ 2111-2122--Fiore, III. Nos. 1341, 1374-1376, and Code, Nos. 1487-1490--Martens, II. § 116--Longuet, §§ 63-75--Mérignhac, pp. 183-209--Pillet, pp. 97-100--Zorn, pp. 174-195--Holland, _War_, Nos. 84-87--Bordwell, pp. 291-292--Meurer, §§ 35-38--Spaight, pp. 202-215, 333-335--Ariga, §§ 98-100--Takahashi, pp. 185-194--Friedemann, _Die Lage der Kriegskundschafter und Spione_ (1892)--Violle, _L'espionage militaire en temps de guerre_ (1904)--Adler, _Die Spionage_ (1906)--_Kriegsbrauch_, pp. 30-31--_Land Warfare_, §§ 155-173--Bentwich in _The Journal of the Society of Comparative Legislation_, New Series, X. (1909), pp. 243-299. [Sidenote: Twofold Character of Espionage and Treason.]