174 EEPORT OF THE ARCHITECTS. 



supplies a pipe system warming one-half of the building. Valves are 

 placed in those 8-inch pipes, and the whole apparatus is arranged so 

 that one, or all, or any number of the four boilers can be used at jjleas- 

 ure and steam shut off from either half of the building, or from any de- 

 sired number of the radiators. The steam-conducting pipes are gradu- 

 ally reduced in size, as the several branches for the supply of the radia- 

 tors are taken off until at the ends of the lines at the northeast corner of 

 the building, which is most remote from the boiler-room, the pipes have 

 but 2 inches diameter. 



The return water-pipes begin at this remote corner with 1^ inch diam- 

 eter and are gradually enlarged as they receive the water of condensa- 

 tion from radiators and mains until they terminate in the receiver in the 

 boiler-room as above described. 



Eising lines of pipes for warming the offices of the second and third 

 stories are attached to the horizontal i^iping, with suitable return-and- 

 relief and air- valve pipes. 



The best provision is made in all lines of i)ij)es for expansion and con- 

 traction by offsets, angles, or expansion joints, as the case requires. 



The horizontal pipes are mainly supported on rollers. All joints of 

 pipes and fittings are made without the use of red lead or cement, the 

 threads being all tapered and exactly fitted so as to be tight when 

 simply screwed together, iron into iron. 



Branch pipes extend out from the main j)ipes, and to these the valves 

 and pipes of 204 upright radiators are screwed. These are all finished 

 in bronze, and contain in the aggregate 13,G00 square feet of radiating 

 surface, which give out the heat generated in the boilers. 



The efficiency of the heating apparatus, though evident, was tested 

 by a series of observations made during the coldest weather of Christmas 

 week. 



During the daytime, with the outside temperature at an average of 

 5° below zero, the interior temperature did not fall below 02^° above 

 zero when but three of the four boilers were in use, the pressure of 

 steam being not above 12 pounds, and the consumption of coal 7,500 

 pounds, for twenty-four hours. 



Observations were also made during the night-time, after all heat had 

 been purposely cut off" from the building and the fires banked, with the 

 mean external temperature at 11^° below zero, the temi^erature within 

 the building did not fall below 48^ above zero. This is a creditable 

 result for the yet incomplete provisions taken against losses of heat by 

 the exposed surfaces. 



The observation is also most gratifying that there is hardly any dif- 

 ference between the temj)erature on the main floor and that of the gal- 

 leries and occupied higher parts of the building abutting on the halls. 

 Thanks to the prompt and efficient co-operation of Col. Thos. L. Casey, 

 the engineer in charge of public grounds, the roads and lawns leading 

 to and surrounding the building were speedily adapted to new grades 

 and verdure restored. 



