140 



its flowers very large and very full, open naturally 

 well ; the color is light carnation rose, — borne on a 

 strong peduncle. It belongs to the series of roses 

 the gardeners call Hybrid Perpetual, (or Remon- 

 tant.) Let us congratulate the jury on its severity 

 in the admission of novelties: it was prudent; for, 

 where there are such quantities of fine things, the 

 greatest reserve is to be observed in recommending 

 new ones." 



Nearly 1,500,000 roses are planted in the neigh- 

 borhood of Brie-Comte-Robert, — a sight for those 

 who visit France next summer. 



Gynernnnpiirpuremn — This variety was produced 

 at the Museum, and flowered for the first time in 

 18G6. Carriere describes it as follows : — Very strong 

 grower, making 6 feet and more in height; leaves 

 stiff, erect, afterwards bending down, deep green ; 

 stems robust, straight, rising above the leaves, ter- 

 minating by an extremely large pamcle, (plume?), 

 well furnished in compact, purple red. This varie- 

 ty begins to bloom in the beginning of September ; 

 it is a very fine plant, very likely the darkest col- 

 ored of all varieties already known. 



Dianthm Perpetual Hyhrid de Roenil, crossing of 

 D. Heddewigii and D. sinensis, dwarf Flowers large, 

 deep velveted brown, centre red, fringed ; first-class 

 plant for edging ; a very good acquisition. Is all 

 the time in bloom, if taken in a greenhouse. Pro- 

 pagates by cuttings. 



THE PSYCHROMETBR IN FURNACE- 

 HEATED ROOMS, &c. 



BY J. S. LIPPINCOTT, HADDONFIELD, N. J. 



It is a common observation that stove-warmed and 

 furnace-heated apartments are unhealthy,and often- 

 times uncomfortable from defective ventilation. 

 Furnace-heated rooms are, however, supplied with 

 abundance of pure external air, and are, sometimes, 

 well ventilated ; yet are disagreeable and unwhole- 

 some to many persons. The conditions unfavorable 

 to health and comfort do not arise from defective 

 ventilation, in a majority of cases, but from inatten- 

 tion to the conditions of moisture or dryness of the 

 air of apartments thus warmed. The importance of 

 due attention to these conditions must become ob- 

 vious from the following considerations : 



Increase in the temperature of the air will induce 

 a change in the proportional quantity of moisture 

 suspended therein. If it be heated, without the 

 requisite addition of moisture, its conditions will be 

 disturbed, and it may be rendered injurious in its 

 action on the human economy. The absolute amount 

 of moisture present is of minor importance to health 

 and comfort ; but the relative amount accompanying 



certain conditions of temperature it most concerns 

 us to determine and adjust. When air is saturated 

 with vapor, at a given temperature, it will receive 

 no more until the heat is increased, when it will take 

 up a greater quantity, if it be accessible. Thus, the 

 air may be saturated at zero, of Fahrenheit, and 

 yet hold less than one grain weight of watery vapor 

 in each cubic foot: it may be saturated at 32°, and 

 hold but 2j grains ; at 70°, and hold 8 grains ; at 

 90°, and contain 14J grains of watery vapor in each 

 cubic foot. On reducing the temperature, air which 

 was saturated will deposit a portion of the vapor it 

 held, though it may still be saturated at a lower 

 temperature, and be, therefore, relatively as humid 

 as before. Hence the term relative-humidity, which 

 expresses the per centage of moisture, — saturation 

 being assumed as the unit. 



From the above, we may readily understand how 

 the air of apartments warmed by furnaces is affect- 

 ed thereby. Air, saturated with moisture at the 

 freezing point or lower, (the temperature at which 

 it is generally introduced into our warm-air fur- 

 naces,) contains from 1 to 2j grains of watery vap-^^r 

 in each cubic foot. Passing into the air chamber of 

 the furnace it may be heated to 100° or much high- 

 er, and enter the rooms above at nearly the same 

 temperature ; when if saturated, it could hold up- 

 wards of 20 grains in each cubic foot, or more than 

 ten times as much as it contains ! 



If this temperature be reduced to 75° by the cool 

 walls, the windows, &c., upwards of grains would 

 be required for saturation, or nearly five times the 

 amount actually present. As dry air, or compara- 

 tively dry air, seeks to become full of moisture, ab- 

 sorbing it as does a sponge, the walls, the furniture, 

 and the inmates of the apartment are subjected to 

 the action of this powerful dryer, and must suffer in 

 consequence. Hence the parching effect upon the 

 skin, throat and lungs, so disagreeable so many per- 

 sons, and so injurious to all inhabitants of furnace- 

 heated rooms, generally. 



The vast importance of just attention to the whole- 

 some condition of the air in family living-rooms, 

 sick rooms, nurseries, lecture rooms, churches, 

 school rooms, hospitals and asylums, and wherever 

 human health may be affected by the reduction of 

 the relative-humidity, renders any instruments by 

 which these conditions may be determined and ad- 

 justed of great hygienic value. To horticulturists, 

 who appreciate the necessity of preserving a certain 

 known state of humidity, or of dryness in their con" 

 servatories, graperies and forcing pits, &c. ; and to 

 the manufacturer, who is aware of the injurious ef- 

 fects of a drying atmosphere upon his fabrics in the 



