4 REPORT OF ARCHITECT OF UNITED STATES CAPITOL. 



falling upon it when the dome was in course of construction that it can 

 no longer be kept weather- tight, and I recommend that a new roof be 

 placed over this portion of the structure the coming building season. 



The heating apparatus of both wings has been kept in good running- 

 order. Of that of the House of Representatives — the running of which 

 the Architect has more immediate charge — Mr. Lannan, the engineer, in 

 his report, says : 



Through the entire session of the last Congress the daily observations commenced 

 last year were continued, accompanied by accurate instrumental tests and measure- 

 ments. Of that which pertained to the heating and ventilating of the hall of the 

 House of Representatives they have been carefully taken, tabulated, and preserved. 

 They show for the period embraced iu the months of December, January, February, 

 March, and April the following results, viz : 



Average relative humidity, per cent - A6-fc 



Average revolution fan per minute 58 



Volume of air carried to hall by each revolution of fan, cubic feet 833 



Volume of air carried to hall per minute taaaaahMMMMMNMtia, cubic 



feet 47,872 



Volume for each person present, per minute, cubic feet 68 . 



Volume removed for each person present, per minute, cubic feet 72 



It will be observed that the volume of air removed was somewhat greater than that 

 delivered. This fact is largely due to the expansion of the air, as the measurements 

 of the air delivered was made at its temperature at the outside, while that of the air 

 expelled was made at the point of exit of the building; where it was heated and con- 

 sequently increased in volume. During the Garfield memorial services, when there 

 were 2,400 persons present in the hall, the machinery and aj»pliances of this depart- 

 ment were severely tested and with most satisfactory results. There were forced into 

 the hall 113.885 cubic feet of air per minute, that being nearly 48 feet to each person 

 per minute. The temperature of the hall was likewise -under easy control, as there 

 was but one degree variation of temperature during this whole ceremony, the ther- 

 mometer ranging between 69° and 70°. 



The small fan has been taken down and reset, and the boilers have been repaired and 

 placed in good order. As these boilers have now been in use twenty-four years, they 

 have been stripped of all their coverings, thoroughly examined, and, to all appear- 

 ances, are perfectly strong andsecure; but during the next recess I am of the opinion 

 that extensive repairs will have to be made to them. I am gratified that as a further 

 measure of precaution you have requested the Secretary of the Navy to detail some 

 of the engineer officers of his department to make a further test and inspection of 

 these boilers. 



The boilers above referred to have, in conformity with an order from 

 the Navy Department, been inspected by Messrs. John Lowe and W. B. 

 Bailey, passed assistant engineers United States Navy, who report as 

 follows : 



The boilers, four in number, were entirely stripped of their brick jackets, thus 

 wholly exposing their exterior surfaces. The fire-boxes were first carefully inspected ; 

 during the time each was undergoing inspection the boiler was subjected to a hydro- 

 static pressure of 110 pounds per square inch, none of the flat surfaces in the fire- 

 boxes showing any signs of weakness. 



The following defects were found, however : 



In furnace No. 1, three patches about the water-legs and one small blister. 



In furnace No. 2, one small crack in the tube sheet and one patch on the water-leg. 



In furnace No. 3, two patches and one blister on the water-legs. 



Iu furnace No. 4, one blister, three patches, and one crack. 



These defects do not materially impair the efficiency of the boilers, but Ave would 

 recommend that the blisters be carefully watched and cut out if they are found to 

 increase. 



The water was then let out of the boilers, manhole plates removed, and the interior 

 of the boilers examined. The boilers are well and sufficiently braced ; the iron, such 

 as can be seen, presents no sigus of corrosion, mud deposit, or incrustation. 



These boilers were built by Ellis & Sons, of Washington, in 1857, and are conse- 

 quently twenty-five years old. Notwithstanding their great length of service, owing 

 to good material and workmanship in construction, careful management, and the use 

 of pure fresh water, we- find them in good condition, and in our opinion perfectly saf( 

 for a working pressure of forty pounds per square inch. 



