Fire is an invader of peace and property, defence against whose destructive forays is one of the first and most constant cares of American cities, old and new, great and small. Before the foundations of the Main Building were laid the means of meeting the foe on the threshold were planned. The Main Building alone contains seventy-five fire-plugs, with pressure sufficient to throw water over its highest point. Adjacent to it on the outside are thirty-three more. Seventy-six others protect Machinery Hall, within which are the head-quarters of the fire service. A large outfit of steam fire-engines, hose, trucks, ladders, extinguishers and other appliances of the kind make up a force powerful enough, one would think, to put out that shining light in the records of conflagration--Constantinople. Steam is kept up night and day in the engines, which, with their appurtenances, are manned by about two hundred picked men. The houses for their shelter, erected at a cost of eight thousand dollars, complete, if we except some architectural afterthoughts in the shape of annexes, the list of the buildings erected by the commission. [Illustration: WOMEN'S PAVILION.] _Place aux dames!_ First among the independent structures we must note the Women's Pavilion. After having well earned, by raising a large contribution to the Centennial stock, the privilege of expending thirty-five thousand dollars of their own on a separate receptacle of products of the female head and hand, the ladies selected for that a sufficiently modest site and design. To the trait of modesty we cannot say that the building has failed to add that of grace. In this respect, however, it does not strike us as coming up to the standard attained by some of its neighbors. The low-arched roofs give it somewhat the appearance of a union railway-depot; and one is apt to look for the emergence from the main entrances rather of locomotives than of ladies. The interior, however is more light and airy in effect than the exterior. But "pretty is that pretty does" was a favorite maxim of the Revolutionary dames; and the remarkable energy shown by their fair descendants, under the presidency of Mrs. E. D. Gillespie, in carrying through this undertaking will impart to it new force. The rule is quite in harmony with it that mere frippery should be avoided within and without, and the purely decorative architect excluded with Miss McFlimsey. The ground-plan is very simple, blending the cross and the square. Nave and transept are identical in dimensions, each being sixty-four by one hundred and ninety-two feet. The four angles formed by their intersection are nearly filled out by as many sheds forty-eight feet square. A cupola springs from the centre to a height of ninety feet. An area of thirty thousand square feet strikes us as a modest allowance for the adequate display of female industry. For the filling of the vast cubic space between floor and roof the managers