98 UNITED STATES NATIONAL MUSEUM 



Vacuum cleaning. — A most important feature of the mechanical 

 equipment is a vacuum cleaning plant, with ramifications to all parts 

 of the building. Besides its application to the ordinary purposes of 

 housekeeping, the usefulness of this apparatus will be especially felt 

 in connection with the cleaning of both exhibition and storage cases, 

 and of their contents, which has hitherto been a slow and laborious 

 undertaking. It may be employed for many classes of objects, and 

 with particular advantage in the removal of dust from fabrics and 

 skins. 



The plant is a stationary one. The machine, located in the engine 

 room, is of the Blaisdell Machinery Company type, and consists of 

 an automatic piston pump connected through a silent chain drive to 

 a 25 horse power motor. Two large tanks are provided in which the 

 dirt-laden air is cleansed on its way to the pump, in the first by 

 centrifugal force, in the second by passing through water. After 

 leaving the pump the air passes through an oil and water separator 

 and is led into the main smoke breeching. From the mains, which 

 run through the tunnels under the ground floor, branch pipes extend 

 to the several stories on which the inlets, to the number of 73, are 

 symmetrically disposed, there being 13 in the ground story, 16 each 

 in the first, second and third stories, and 12 in the attic. The inlets 

 are mostly located on piers about 2 feet above the floor and measure 

 IJ inches, while the size of the riser pipes is 3 inches. The inlets are 

 closed by means of brass caps with soft lead gaskets to prevent leak- 

 age. The dust hose employed is of rubber, in lengths of 25 and 50 

 feet, and is attached for use to the inlet nearest the place where 

 cleaning is to be done. A complete equipment of dusting tools has 

 been provided. 



Ice plant. — For the manufacture of ice the building contains a 5-ton 

 refrigerating machine, supplied by the Brunswick Eefrigerating 

 Company. It occupies a small room near the entrance under the 

 south portico, and is of the compression type, being driven by a 

 silent chain from a 7^} horse power motor. Its capacity is two tons 

 of ice every twenty-four hours. The freezing tank measures 21 feet 

 8 inches by 9 feet | inch and contains fifty-four 200-pound cans. 

 The circulation of the brine in the tank is produced by means of a 

 f -inch volute pump driven by a belt from a ^ horse power motor. A 

 hoist running on a track along two opposite walls of the room serves 

 for the removal of the cans. A still smaller adjoining room has been 

 adapted to the storage of ice by lining its walls and ceiling with sheet 

 cork covered with cement plaster, and providing a suitably drained 

 cement floor and a door of cold storage pattern. 



Drinking water service. — For supplying drinking water, a number 

 of cooling tanks have been installed in the attic with distribution 

 pipes leading to outlets in the several stories. There are six of these 



