Surrounding Utrecht and penetrating far to the east and the south are the great fortifications, of whose presence the casual observer is entirely unaware, belonging to the first line of national defense that might be used to protect the Dutch capital from invasion--a defense in which she seeks the assistance of her mortal enemy, and discovers him weighed in the balance and not found wanting. Upon a process of general inundation, by fresh water wherever possible so as not to impair the future productiveness of the fields, does Holland depend for her safety from invasion both by land and by sea. In the probability of the latter, her power of self-exclusion is augmented by a treaty with Belgium, signed in 1892, confirmed in 1905, and only recently made public, reserving for her the right to block the great estuary of the Scheldt in case of war or rumors of war. In times of peace Belgium shares with the Netherlands all rights of navigation of the Scheldt, and Holland may not displace or remove buoys, lights, or other aids to navigation, without Belgian consent. [Illustration: The lower end of the Oude Gracht, Utrecht, a canal which in its upper part is at a level far below the street, giving space between the foundation walls for shops and even homes] But with regard to Holland’s ability to isolate herself by general inundation, it is a scheme that gives little outward evidence of being in operation. A stranger might roam within her boundaries for a year and a day without even surmising that such a thing could be accomplished, so successfully are her greatest works hidden from the eye. The scheme provides, in brief, for the blowing up of railway bridges and for the opening of the sluice gates of great reservoirs, regulating the amount of water to be poured in over the country so that it should all be of the same depth, prohibiting both the possibility of wading through it and the passage of vessels over it. A half a day, if time presses, will suffice to see Bois le Duc. After you have wandered about in its great Gothic cathedral of St. John, one of the largest and, by all odds, the fanciest church--if a church can be said to be fancy--in Holland, you will have done with the town. It holds nothing else of interest. Although of 32,000 population, and the capital of the Province of North Brabant, it is dull and unappealing to the tourist. There are few types and few distinctive mannerisms. Of its costumes, the only feature is a headdress, affected by some of the countrywomen of the surrounding district, composed of white lace and topped with garlands of artificial flowers as ridiculous and disappointing as the “poke bonnets” worn by the middle-aged matrons of Leeuwarden, and just as out of place.