VERDI. 



733 



heating surface as possible in order that the cold air 

 introduced may become sufficiently warmed before 

 passing into the various parts of the building, a fur- 

 nace should be built upon the same principle us a tubu- 

 lar boiler and enclosed to prevent the escape of the air 

 which is being warmed and collected in the dome, suf- 

 ficient space being allowed between the enclosing walls 

 and the furnace to permit the warming of a certain 

 amount of air introduced from without. Steam-coils 

 and hot water pipes are also arranged to secure the 

 greatest amount of heating surface possible, and simi- 

 larly enclosed. Small portable furnaces, such as are 

 found in ordinary dwelling-houses, are enclosed by 

 sheet-iron instead of brick, the cold air entering from 

 the bottom and becoming warmed as it passes upward 

 into the drum. 



The hot air is now ready to be conducted into the 

 room or hall : the question is, where shall it enter ? The 

 consensus of opinion now is, that it should be admit- 

 ted at or near the floor, for reasons already given. 

 Shall it be drawn in by vacuum, or forced in by pro- 

 pulsion, or shall both aspiration and plenum be em- 

 ployed ? If by vacuum, where shall that be applied, 

 near the ceiling or at the floor ? As before stated, the 

 Halls of Congress are heated and ventilated by plenum, 

 the heated air _in winter and the fresh air in summer 

 being forced in by means of a large fan-wheel, 

 through numerous openings in the floors, carrying with 

 it the dust and other impurities which naturally gather 

 there, while louvers or ridge ventilators are placed at 

 or near the roof. It is claimed, too, that the floor 

 registers are used as cuspidor?, and that the general 

 sanitary conditions of the nails is detrimental to heulth 

 on account of the system of heating and ventilation 

 employed. The more recent and scientific application 

 of the forces of nature as developed by the vacuum or 

 down-draft m/xtfm may be here explained : A vacuum 

 is created in a heated shaft outside the building ; the 

 rooms or halls to be ventilated are connected with this 

 shaft by numerous ducts opening upon the floor, the 

 number and size of the openings depending on the air 

 space to be ventilated ; at or near tne ceiling fresh air 

 is admitted through numerous openings and in the 

 same proportion as it is withdrawn below; this in sum- 

 mer or moderate weather. In winter the heated air is 

 admitted near the floor, naturally ascends, and (the 

 openings in the ceilings being closed) distributes itself 

 equally throughout the room and finds its exit at last 

 through the foul air duct openings at the floor. Ob- 

 jection is made that heated air will remain at the top 

 of the room : theoretically it will ; but experiments 

 have proved that it docs not, when a vacuum is created 

 below ; on the contrary it is discharged as rapidly as it 

 enters, but not till after it has become equally diffused 

 throughout the room, the thermometer marking but 

 two or three degrees difference between the top and 

 the bottom of the room. In fact, the expansion of air 

 by heat is only jj^ of its volume for every degree (P. ) 

 of additional temperature ; if it is zero outside and 70 

 inside, the air in the room will bo only one-seventh 

 lighter than the outside air. By placing the ventilat- 

 ing shaft and chimney side by side (carrying them 

 both well up above the building) the former will be 

 sufficiently heated for ventilating purposes in ordinary 

 weather, but on damp mucky days, or in summer, 

 when the chimney is not heated by fire, a small furnace 

 is necessary to create a vacuum in the shaft. An ex- 

 haust-fan is substituted for the ventilating shaft, when 

 desired, and acts on the same principje, oy creating a 

 vacuum upon the floor of the room which, the warm air 

 above at once fills. Both propulsion and vacuum are 

 employed in mines, aboard ships, and for inaccessible 

 spaces. 



/'iii-e Air. The question of obtaining pure air for 

 heating and ventilating purposes is much discussed, 

 many believing that it cannot be had at the level of the 

 lot or street upon which the house is built, and pure 

 air shafts of various heights have been suggested. 



Others claim that smoke, cinders, and the products of 

 combustion in a large city would be drawn into shafts 

 and that the air circulating upon the surface of the 

 earth is best. All agree, however, that air from cel- 

 lars, damp basements, newly made earth, foul streets, 

 or marshy grounds is not fit to use. This question 

 must be settled by the circuiustauces involved in each 

 case. 



The system of ventilating and warming introduced 

 by Gouge of New York, based on the increased force 

 air gains by being gathered into different sized tubes, 

 partially inserted one into the other, and started by 

 means of a gas jet or lamp, is novel and said to be very 

 satisfactory, particularly in large buildings and railroad 

 cars, where it has been pretty extensively adopted. 



The Ruttan-Smead system is fast becoming very 

 popular, many school-houses and public buildings being 

 heated and ventilated by it. The principle is the down- 

 draft or vacuum system, with the additional advantage 

 of utilizing the heated air after it has left the rooms or 

 halls by its passing through numerous openings under 

 the floors, thus keeping them warm, and being again 

 collected in a "gathering-room," where it is further 

 used for ventilating the privies and urinals located in 

 the basement, it thence passes into the heated venti- 

 lating shaft. The furnace is tubular, and so con- 

 structed as to not only secure a large heating surface 

 but also obtain much heat from the gases and smoke 

 before they escape into the chimney. The ventilating 

 shaft and chimney are carried well above the building 

 and are separated by a thin partition which keeps the 

 shaft heated when the furnace is in use, and a small 

 furnace supplies heat when it is not in use or on damp 

 or rainy days. Each room is supplied with a separate 

 fresh air duct entering near the floor, which is so ar- 

 ranged as to let in either warmed air or cold air, or a 

 mixture of both, as may be desired. An examination 

 by the writer of the "gathering-room" and the 

 privies of a twelve-room school-house with 480 schol- 

 ars demonstrated the practibility of thoroughly deo- 

 dorizing and drying the deposits, an accumulation of 

 two years from this number of pupils giving off no 

 odor and appearing like a few barrows of dark dry 

 earth, the urine and all moisture having evaporated. 

 The down draft through the privy holes was very 

 strong and constant, and no odors were perceptible. 



No other new systems of ventilation and warming 

 have been introduced in late years ; perhaps there are 

 none that do not embrace one or more of those already 

 described. (p. H. B.) 



VERDI, GIUSEPPE, the foremost of modern Ital- 

 ian composers, was born at Roncolo, near Parma, Italy, 

 Oct. 9, 1814, his father being a poor inn-keeper. From 

 his earliest years he manifested a talent for music, and 

 at the age of eight began to receive lessons from the 

 village organist, while also attending a day-school at 

 Busseto. At his eleventh year a liberal amateur of 

 that town received him into his house and put him un- 

 der the organist of that place, where he already began 

 to write little orchestra-pieces. In 1833, through the 

 bounty of his patron, he was able to go to Milan, and 

 received for three years instruction from Lavigna, 

 maestro in the great theatre, La Scala. Thence he re- 

 turned to Busseto, and in 1839 married the daughter 

 of his benefactor. Then taking up his residence in 

 Milan, he brought out his first opera, Cunte di San 

 Bonifazlo, at La Scala. Such was its success that he 

 forthwith received a commission from the director for 

 three other operas, to be produced in two years. The 

 first he presented was a comic opera, Un giorno di 

 reyno, which met with but a cool reception, and this, 

 coupled with the death of his dearly loved wife, deter- 

 mined him to renounce comic opera forever. His next 

 work. Nabucndonosor, was performed at La Scala 

 with triumphant success during the carnival of 1842. 

 From that hour the young master took rank among the 

 first composers of the age. His I^Lombardi appeared 

 at the same theatre in 1843, and his Ernani at Venice, 



