Feb. 5, 1880] 



NA TURE 



The author has collected the following series of rainfall obser- 

 vations, all of which contain more than fifty years' records. 



Padua 



(Symons* 



tabic) 



Milan 



London 



Madras 



Philadelphia ... 



Edinburgh 



New Bedford ... 



Rome 



172') to 1865 

 1764 to 1S78 

 1815 to 1878 

 IS13 10 1877 



1810 to 1867 



1822 to 1878 



1814 to 1867 



1825 to 1878 



No. of 

 years. 



Denza. 



£66. 



Denza. 



Annuaire de 

 vat> ire <le 



MSS. from P. 



B.A. Report. : 

 MSS. from P. 

 Dines and Symons. 

 Nature, vol. xviii. ] 



505- 

 Smithsonian 1 able 



p. 97. 

 Natuke. vol. xviii. ] 



97- 

 Smithsonian Table 



p. 90. 

 MSS. frum P. Denz: 



To these he added an eleventh, forming a series by com- 

 bining together the annual rainfall for 1822 to 1S75 at London, 

 Paris, and Edinburgh, which increased the total number of years 

 of observations to 978. 



These he has discussed after a method described at length in 

 the paper, and determined for every series the curves which 

 represent the variation in the means of the amount of annual 

 rainfall for each of the years comprising the series on the 

 assumption of the presence of a cycle, which he varies in dura- 

 tion from five to thirteen years. 



The computed curves are then compared with the actual curves 

 representing the observations, and the number of coincidences 

 and non-coincidences in the epoch of maximum and minimum 

 determined. 



The results show that in no one case is there any indication of 

 a period of any integral number of years from five to thirteen 

 inclusive running through them. 



It also became evident that for the same epoch the curves of 

 variation differ widely for localities comparatively close together. 

 For example, taking the eleven-year cycle for Padua and Milan, 

 stations only about 130 miles apart, both well situated for 

 observing rain, and no mountain range intervening, the variation 

 curves are as follows : — 



These show that the years of greatest rainfall at Padua are 

 represented by the formula [1804 or 5 +• ll»], and of least by 

 [1806 + II*], whilst for Milan the maximum occurs at 

 [1807 + ll«], and the minimum at [1S08 + iix]. 



Numerous other instances of incongruity are found in every 

 one of the cycles, leading forcibly to the conclusion that either 

 no short term of exactly five, six, seven, eight, nine, ten, eleven, 

 twelve, or thirteen years exi>ts in the annual amount of rainfall 

 at any of the stations whose observations have been discussed in 

 the paper, or that the effect of abnormal falls is so great that it 

 cannot be eliminated by upwards of a hundred years' observa- 

 tions. 



In any case the author thinks it may now be stated with 

 certainty that all predictions as to rainy or dry years, based upon 

 existing materials, must in future be considered as utterly 

 valueless. 



Zoological Society, January 20. — Prof. Flower, F.R.S., 

 president, in the chair. — Mr. H. N. Moseley exhibited and made 

 remarks on some microscopic preparations of corals made by a 

 new method invented by Dr. G. V. Koch. — Prof. Flower, 

 F.R.S., read a letter addre-sed to him by Col. Heysham, of 

 the Madras Commis-ariat Staff, sjiving particulars of two cases 

 of female elephants, in India, having produced young in cap- 

 tivity. — l>r. A. Gunther, F. R.S., exhibiied and made remarks 

 on a drawing of a West Indian fi*h (Holacanthus tricolor) ob- 

 tained on the coast of the Island of Lewis, and believed to 

 have been found for the first time in the British Seas. — Mr. P. 

 L. Sclater read some remarks on the species of the genus 

 Tyramuis, in relation to a paper on this subject recently pub- 



lished by Mr. Ridgway, in America. — A communication was 

 read from Mr. Roland Trimen, containing an account of a new 

 species of Roller (Coraeias), from the Zambesi, which he pro- 

 posed to name C. spatulala, from its long spatulated tail.— A 

 communication was read from Mr. Alexander Agassiz, of Cam- 

 bridge, Mass., containing notes on some points in the history of 

 the synonomy of Echini, in reference to some papers recently 

 published by Mr. Bell in the Society's Proceedings. — A paper 

 was read by Mr. F. Moore on tbe genera and species of the 

 lepidopterous sub-family Ophiderina, inhabiting the Indian 

 region. 



Physical Society, January 24.— Prof. \V. G. Adams in the 

 chair.— New member, Mr. W. Ellis. — Mr. Grant rend a paper 

 and exhibited experiments on induction and telephonic circuits. 

 He was led to these experiments by a former observation that 

 when an induction coil primary was placed in a circuit consisting 

 of a telephone, microphone, and battery, the microphonic sounds 

 heard in the telephone were increa-ed on closing the secondary 

 circuit of the coil. Employing a double round coil, that is 

 having primary and secondary side by side, he found that the 

 latter could act as a condenser, and "relay" or translate 

 mes-ages into a second circuit, the microphone and battery 

 being in the circuit of one wire (i.e., the primary), the 

 other wire (or secondary) containing a telephone. He 

 also inserted a double normal coil in the latter or secondary 

 circuit, and caused the induced or translated current to flow 

 through both of the wires of this double coil one after another in 

 the same direction. The effect was weak ; but on reversing the 

 current in 1 ne-half of the double coil by means of a commutator, 

 so as to make it double on itself as it were, the weakening effect 

 of induction was neutralised, and the sounds heard were as loud 

 as if no coil had been inserted in the secondary circuit at all, as 

 was proved by short circuiting the double coil altogether. — 

 Dr. O. J. Lodge read a paper on intermittent currents and the 

 theory of the induction balance. The telephone, as a scientific 

 instrument, seems destined to play an important part as a detec- 

 tor of minute currents of rapidly changing intensity, and the 

 general theory of intermittent currents is being brought into 

 prominence by its use. The equations to which most attention 

 has been hitherto directed have been those relating to the steady 

 flow of a current after the initial inductive or inertia-like effects 

 have subsided. The galvanometer is essentially an instrument 

 for measuring steady currents or for giving the algebraically in- 

 tegrated expression for the total quantity of electricity which 

 has passed in the case of transient currents. But the telephone 

 plate has a very small period of sw ing compared to a needle, 

 and, moreover, the plate is not limited to one mode of vibration 

 like the needle. The induction balance was used experimentally 

 by Dove and Felici, but was not appreciated as an instrument of 

 research till Prof. Hughes applied it to the telephone and an inter- 

 mittent current. The general theory of the establishment of 

 a current in circuits of known resistance was given by Thomson, 

 and is to be found in Maxwell's " Electricity." Dr. Lodge used 

 this theory in order to work out the theory of the induction balance 

 and one or two other cases of intermittent currents as completely 

 as possible without taking into account the electrostatic capacity of 

 wires and leakage. The current in either primary of the balance 

 is the same, and the current in either secondary is the same at 

 every instant of time. In fact, the separating of the two halves 

 of the circuits is immaterial to the theory. The current induced 

 in the secondary circuit is a tertiary current induced from the 

 piece of conducting matter inserted between the primary and 

 secondary, an expression being got for the strength of current in 

 the telephone at any instant after a change in the resistance of 

 the primary has occurred. The author deduces among other 

 things the law according to which a small coin, by its position 

 and size, disturbs the balance. Dr. Lodge remarked that Prof. 

 Hughes, either by inventive intuition or great pains, had 

 hit upon the best form of the apparatus for his purpose. 

 The piper, which is very complete, is to be published in 

 the Philosophical Magazine for February. — Herr Faber then 

 exhibited bis new speaking machine which is designed to 

 imitate mechanically the utterances of the human voice by 

 means of artificial organs of articulation, made on the human 

 model, and actuated by an operator who depresses certain 

 keys as in playing a musical instrument. These organs are a 

 bellows made of wood and india-rubber, which answers to the 

 lungs ; a small H imlmill brought in front of the latter to give the 

 "r," or trilling sounds, a larynx of hippopotamus hide and 

 india-rubber having a vibrating end, to give the "drone" or 



