The suggestion of Bourseul and the experiments of Reis are founded on the idea that a succession of currents, corresponding in number to the successive undulations of the pressure on the membrane of the transmitting instrument, could reproduce at the receiving station sounds of the same character as those produced at the sending station.
His aim was the production, by means of the undulations of pressure on a membrane caused by sound, of an electric current the strength of which should at every instant vary directly as the pressure varied).
The vast number of microphonic contacts present give rise to very strong electrical undulations, and hence to a loud sound.
The vas deferens descends with many undulations down the lateral side of the ureter of the same side, and opens upon a small papilla into the urodaeum.
The undulations are scarcely apparent.
It is beautifully situated on high ground among the wooded undulations of the North Downs, above the valley of the river Darent.
In each direction the country falls away in a succession of minor undulations, the summits of the ridges being occupied by the streams and bayous.
It extends as a completely even plain of snow, with long, almost imperceptible, undulations or waves, at a height of 7000 to 10,000 ft., obliterating the features of the underlying land, the mountains and valleys of which are completely interred.
To the north of these mountains, stretching towards the Danube, is the Alpine foothill region, composed partly of terraces and partly of swelling undulations, of which the most important is the Hausruckwald.
North of the Thames, and west of its tributary the Lea, which partly bounds the administrative county on the east, London is built upon a series of slight undulations, only rarely sufficient to make the streets noticeably steep. On the northern boundary of the county a height of 443 ft.
Below the hills the country is high and arid, generally level, but sometimes rolling in sandy undulations, and much intersected by hill torrents, 201 in number.
The boundary between, the grey cylinder and the black fork will therefore appear wavy with fixed undulations, the distance from crest to crest being the distance between the lines on the cylinder.
Light is therefore an influence propagated as wave-motion, and moreover by transverse undulations, for the reasons brought out by Thomas Young and Augustin Fresnel; so that the aether is a medium which possesses elasticity of a type analogous to rigidity.
We shall make the natural supposition that motion of the aether, say with velocity (u,v,w) at the point (x,y,z), is simply superposed on the velocity V of the optical undulations through that medium, the latter not being intrinsically altered.
The eastern portion of the district is generally flat, broken only by gentle undulations, but the western parts, from north-west to south-west, are intersected by the great Aravalli range.
Adis Ababa stands on the southern slopes of the Entotto range, at an altitude of over 8000 ft., on bare, grassy undulations, watered by small streams flowing S.S.E.
She is able not only to distinguish with great accuracy the different undulations of the air and the vibrations of the floor made by various sounds and motions, and to recognize her friends and acquaintances the instant she touches their hands or clothing, but she also perceives the state of mind of those around her.
It is wonderful with what elaborateness this simple fact is advertised--this piscine murder will out--and from my distant perch I distinguish the circling undulations when they are half a dozen rods in diameter.
Though I passed over it as gently as possible, the slight undulations produced by my boat extended almost as far as I could see, and gave a ribbed appearance to the reflections.