247 



of the same uietal, the ceuter of the stopper having an aperture of 1.5 millimeters, 

 slightly conical, with the base greater towards the exterior. 



At the base of this cylindrical box there is an aperture whose axis is in the direc- 

 tion of' a tangent to the concave surface of the cylinder. This aperture communi- 

 cates with a pump by means of an India-rubber tube, which is the distributor. The 

 liquid enters the cylinder with great velocity, there existing a great difference in 

 diameter between the distributing tube and the receiving aperture. By the tangen- 

 tial position of this aperture the liquid is forced to whirl in the cylinder, assuming 

 a rapid rotary motion. When the liquid has tilled the cylinder it is forced to pass 

 out by the upper aperture. The molecules of the liquid, continuing this rapid cir- 

 cular movement until the exit is reached, are thrown by centrifugal force first upon 

 the surface of the conical aperture and afterwards into the outer air by combined 

 forces of projecting and rotary motion. When the spirals have reached such a size 

 as to overcome the molecular atttactiou of the liquid they are subdivided into mi- 

 nute particles forming a mist or spray of extreme fineness. 



Dr. Alpe follows with a leDgthy discussion as to the availability of 

 the Riley uozzle for spraying lime water, and concludes that from the 

 nature of the small exit aperture they are not suited to this work. 



Professor Scribner, while mycologist of this Department, found, how- 

 ever, that the Yermorel modification of the Eiley nozzle (which will be 

 spoken of at greater length further on) is the- only nozzle he can use 

 successfully in applying lime-water. 



Continuing, Dr. Alpe speaks of the more important modifications of 

 this nozzle which were shown at the exposition, as follows: 



In truth, Vermorel, who now constructs the Riley atomizer in France, has endeav- 

 ored to find a remedy by enlarging the aperture of exit as much as the peculiarities 

 of the construction will admit. 



From this it is easily imagined that various persons have thought of modifying 

 the original apparatus of Riley, and among the most noted modifications and 

 which deviate less from the primitive type, and which we saw at the exposition, 

 are those of Ronfini, of Venturiui, of Barnabe, of Savoia, of Professor Giordano, and 

 of Noel. 



The first content themselves with slight modifications, while the latter introduce 

 much more radical changes. Ronfini modified the Riley atomizer more in the form 

 than in the essential parts, but Venturiui has rendered it much better adapted to the 

 use of hydrate of lime; not only enlarging the circumference, but at the same time 

 furnishing the lower base with a regulator by means of which the jet may be made 

 to bear a greater or less atomizing, according to necessity. Barnabe, instead of this, 

 contrived to avoid the clogging of solid material by attaching a screw to the lower 

 opening in such a manner that it can be opened and closed in an instant, causing the 

 substance which impeded the regular functions of the apparatus to fall of itself, pushed 

 bjf the liquid which continues to flow. 



Savoia placed the air-chamber higher, and in the wall of the receiving-cylinder 

 fixed four blades, which, arranged one above the other, forced the liquid, which 

 rushed from a small lateral aperture, to strike successively from one to the other, 

 revolving twice. More reasonable and better adapted to the apparent object is the 

 Giordano atomizer. This, as usual, is formed of a chamber jilaced immediately above 

 the place of exit for the liquid from the pump, which is furnished with a thin, mov- 

 able plate of metal about half way up, having four apertures of sufficient extent placed 

 at an angle of 45 degrees. The solution then strikes against the metal valve before 

 mentioned, divides itself into four parts, and these four jets then reunite, striking 

 one against the other, rush violently into the upper part of the apparatus, there 



