May, 1904.] 



KNOWLEDGE & SCIEXTIEIC NEWS. 



93 



Britain, have failed to find any trace of the rays as ol)jecti\ c 

 realities ; Professor C. C. Shcnolc has criticised, in a way which 

 demands an answer, M. Blondlot's experimental methods and 

 his alleged measurement of the N -ray's wave length ; and Herr 

 O. Lummer has suggested, in a paper read before the German 

 Physical Society, that the observed phenomena are due to pro- 

 cesses in the retina of the eye (•• the contest between the rods 

 and cones of the retina "). Meanwhile, the French observers 

 go on undismayed by the stain of criticism and objection, and 

 in Cosmos (April 2) Professor A. Charpentier gives the result 

 of his observations on the connection between X-rays and the 

 sense of smell. The N-rays, he observes, exercise a very dis- 

 tinct action on the olfactory sense. It can be shown if the 

 nose is approached during the action of smelling by a body 

 capable of producing N-rays, such as a piece of tempered steel 

 or the closed fist, that the sensation of smell is increased. The 

 experiment must be made with all necessary precautions, in 

 still air, very slowly, with gentle and regular breathing, the 

 odorous substance being maintained at a fixed distance nearly 

 approaching to the extreme limit at which the olfactory organs 

 can perceive it. The source of N-rays can either stimulate 

 the sense of smell when the limit of perception is almost 

 reached, or increase its intensity where it is already in exist- 

 ence. In both cases, the action is perceptible. It takes place 

 when the source of the rays is approached to the root of " the 

 nose or the base of the nostrils." If the mass of muscles in 

 the thumb are placed against the nose, the slightest contrac- 

 tion of these muscles produces the effect already mentioned. 

 Essence of cassia was the odorous substance usually made use 

 of by Professor Charpentier, but the same results have been 

 obtained by him from very different scents — essence of 

 lavender, thyme, cloves, mint, camphor, ether, iodoforme, 

 ammonia, and acetic acid among them. The N-ray action 

 penetrates thin sheets of aluminium, and it is useful in order 

 to eUminate the currents of air produced, in spite of all pre- 

 cautions, by displacing the source of the rays, to place a large 

 sheet of this metal against the outside of the nose, and to con- 

 duct the experiment on the other side of it. 



N-rays can, moreover, influence the olfactory sense when 

 thev are made to act at certain points on nerve centres if, for 

 instance, the substance, which is the source of the N-rays, is 

 placed near the middle of the forehead immediately above the 

 place where the eyebrows meet. The effect is especially 

 striking when the source of the rays is placed on the summit 

 of the cranium a little in front of the place of union of the 

 frontal and the two parietal bones. 



This effect of N-rays is not confined exclusively to the 

 organs of perception. The scent is increased to some extent 

 when the radiating source is put near the flask containing the 

 odorous substance at too great a distance from the nose to 

 influence it directly. Professor Charpentier continues: "In 

 the same way I have observed that the substances thus 

 mentioned distinctly emit N-rays which traverse cork, and alu- 

 minium, but are stopped to a great extent by lead, and can 

 give rise, like the other sources, to secondary radiations. As 

 for the action of N-rays on the other senses, I have found, to 

 begin with, a very distinct effect on the sense of taste. If a 

 trace of some highly flavoured substance is put on the end of 

 the tongue such as camphor, aloes, salt, or sugar, keeping the 

 mouth open, the breath held, and the palate raised so as to 

 avoid all olfactory influence, the approach of a radiating 

 source, such as a ball of tempered steel, reinforces or creates 

 the sense of taste. The same thing happens when salt or 

 other substance is diffused in the mouth instead of keeping it 

 on the end of the tongue. .Are there points of the brain on 

 which N-rays can act by determining an increase of the sense 

 of taste? After experiments with different parts of the 

 cranium, I h.ave only found a certain degree of action in one 

 parietal zone, next to that which acts on vision, perhaps a little 

 behind it. The study of hearing is more difficult, because of 

 the precautions to be taken in order to prevent the currents 

 of air displaced by breaking the source of radi.ition interfering 

 with the conditions of arrival of the sound. It can be done, 

 however, by making use of secondary radiations. Now, in 

 taking as the .source of sound a watch held at the extreme 

 distance at which the sense of hearing c-an perceive it, I have 

 only clearly proved some increase of sound when the terminal 

 plate was placed right above the ear at 7 to S centimetres from 

 the orifice of the ear, which appears to confirm the idea of an 

 excitation affecting the central centres of hearing. 



The Single-Phase Motor 

 in Germany. 



Thi-: single-phase tr.ictiou motor which has been designed 

 by the Union IClectric Company, Berlin, according to Wmter 

 and luchberg's data, and which is being tried on the Johan- 

 nisthal-Spindlersfeld suburban line, near Berlin, is thus de- 

 scribed bv our Berlin correspondent : 



The motor includes a stator similar to those of ordinary 

 induction motors, containing a single-phase coil arranged in 

 notches, and a collector armature which is designed like the 

 armature of a direct current motor, and to which two sets of 

 brushes with axes perpendicular to one another are fixed. 

 The first set, the axis of which coincides witli the axis of the 

 stator coil, is short-circuited. It carries tlie working cmrents 

 proper. These are induced by the field in the direction of 

 the axis of the stator coil of a series transformer that is niserted 

 in the main-current circuit, and carries only magnetising cur- 

 rents. The magnetising currents produce a transversal field 

 F perpendicular to the field </>. by which, in conjunction with 

 the stator current, the efficient torque is produced. The 

 presence of two separated fields enables the motor to work 



5ingle"Phase Motor in use on the Spindlersfeld Railway. 



without sparking. The electro-motive force generated in a 

 winding that is short-circuited by a brush through the induc- 

 tion of the field F is perfectly compensated as the speed of 

 revolution increases, by the electro-motive force due to the 

 rotation in the second field ip. That would be impossible in the 

 case of monophase series motors, where, in the winding short- 

 circuited through a brush, an electro-motive force independent 

 of the number of turns, and incapable of being compensated, 

 is induced. 



Moreover, by the rotation of the armature, an electro-motive 

 force is induced in the exciting circuit of the armature which 

 is able not only to compensate perfectly the undesired electro- 

 motive force of self-induction of the circuit, but at the same 

 time the electro-motive force correspondmg to the primary 

 and secondary leakage. With an increasing number of revolu- 

 tions the power factor will thus approach the value cos <(> = i, 

 this value being maintained constant within wide limits on 

 account of the unique regulation. Without any prejudice to 

 motor efficiency, the air gap may therefore be made as great 

 as in the case of direct current motors, and open stator 

 notches may be used instead of closed notches. The ratio of 

 the exciting' transformer is regulated by the insertion or dis- 

 connection of windings. In the case of the series transformer 

 being adjusted for a given ratio the motor will behave in a 

 way (juite similar to direct current series motors, lioth the 

 current intensity and the torque having the maximum value at 

 rest and decreasing for incre.ising angular speeds. In the 

 case of the ratio of the series transformer being diminished, 

 the characteristic curve of the motor is displaced so as to 



