652 



NATURE 



\OcL 17, 1878 



will no doubt be placed in the hands of some competent German 

 palceontologist for description. It is said to be in several re- 

 spects more perfect than the first, and hitherto unique, speci- 

 men in the British Museum, which has been the subject of the 

 labours of Prof. Owen and Prof. Huxley on this most remark- 

 able of extinct birds. 



The death is announced of M. Leymarie, Professor of Geology 

 at Toulouse, and the author of the first geological map of 

 France. 



The death, at the age of seventy, of Prof. William Monroe 

 Davis, is announced as having taken place at Cleveland, Ohio, 

 U.S., on July 21 last. When quite advanced in life Prof. 

 Davis took up the study of astronomy, and has long been 

 known as an original thinker and labourer in this field. After 

 the resignation by Prof. Mitchell, as director of the Cincin- 

 nati Observatory, he was succeeded by Prof. Davis, who 

 remained in charge for some considerable time. Of late years 

 ie has not been actively employed in rny work, with the excep- 

 tion of the construction of a telescope, which has done excellent 

 service in his hands. 



The Society of Arts announce that their opening meeting 

 will be held on November 20, when the chairman's inaugural 

 address will be delivered and the following medals presented : — 

 The Albert Medal (gold), for " Distinguished Merit in Pro- 

 onoting Arts, Manufactures, or Commerce," to Sir William 

 G. Armstrong, C.B., F.K.S., D.C.L. The council also 

 announce that the following papers will be read : — On Novem- 

 ber 27, " The Land of Midian," by Capt. Burton ; December 4, 

 "The Electric Light," fully illustrated with experiments, by 

 T. N. Shoolbred ; December 11, "The Route to India, with 

 •especial Reference to the Euphrates Valley Railway," by Hyde 

 Clarke ; December 18, " Science Teaching in Elementary 

 Schools," by Dr. Gladstone, F.R.S. ; and the first course (six 

 in number) of lectures by W. M.Williamson " The Manufacture 

 of Mathematical Instruments." 



A CORRESPONDENT makes the interesting suggestion that the 

 microphone might be used to detect if insects have any audible 

 means of communicating with each other, and if so, what is its 

 nature in different classes of insects. 



The fourth annual conference of the Cryptogamic Society of 

 Scotland was held in the Royal Botanic Garden, Edinburgh, on 

 the 9th, loth, and nth inst., under the presidency of Prof. 

 Balfour, and was a success in every way. The business meeting 

 •was held in the lecture-hall, and in addition to the president's 

 address a number of papers were read relating to recent dis- 

 coveries—both in species and in morphology — in cryptogamic 

 botany. An excursion was made to the Penicuick woods, where 

 about 170 species of fungi, including one or two new and several 

 rare species, were noted. The public show was held in the 

 winter garden and herbarium of the Royal Botanic Garden, and 

 was visited by a great many people, who appeared to be much 

 interested in the exhibition. A considerable number of hymeno- 

 mycetes, &c.. Mere arranged in classified order and named. 

 Many distinguished botanists, both English and Scottish, at- 

 tended the meeting, and were very hospitably entertained by the 

 president and other members of the local committee. A notice 

 of the scientific results of the conference will be given in the 

 Scottish Naturalist. Next year's conference is to take place at 

 Forres. Arrangements may be learnt from the secretary of the 

 Society, Dr. Buchanan White, Perth. 



Mr. T. Muir, M.A., of the High School, Glasgow, has 

 forwarded to the London Mathematical Society a verification of 

 Pervouchine's first result regarding the divisibility of 2* -f i 

 by 7'2^* + I (Nature, vol. xviii. p. 104). The mode of veri- 



fication will be understood from the following question and 

 solution : — Is 1 1 '2* -f i a factor of any number of the form 

 2™ -h I ? 11*2* -1- I = 2'' + 2^ -h 2* -f I = loiioooi (radix 2j, 

 The question thus is — " Is there any number which when 

 multiplied by loiioooi will produce a number of the form 

 1000. . . 0001 ? Now knowing that the last digit of the multi- 

 plier and product is i, we infer that the last digit of the multi- 

 plicand must be I. Taking it as such and performing the 

 multiplication we have — 



whence, in order that the result of the addition may be of the 

 form . . . .0001, we see that the second, third, fourth, and fifth 

 digits of the multiplicand must be o, o, o, i respectively. Pre- 

 fixing these to the first digit and continuing the multiplicatron 



we have — 



... .10001 



lOIIOOOI 



. . . .lOOOI 

 . ...lOOOI 



. . .10001 

 .10001 



from which on addition we deduce other four digits of the 

 multiplicand ; and so on. When we have got in all twenty-two 

 digits the figuring is as follows : — 



lOI I lOOIOOIOOOOIOIOOOI 

 lOIIOOOI 



lOI I lOOIOOIOOOOIOIOOOI 

 lOI I lOOIOOIOOOOIOIOOOI 

 lOI I lOOIOOIOOOOIOIOOOI 

 lOI I lOOIOOIOOOOIOIOOOI 



and we find that addition then gives a product of the required 

 form ; and thus we have the result — 



2^» -J- I is divisible by 11 '2* -f i. 

 When there are few significant figures in the multiplier, as here, 

 it will readily be seen that a very considerable lessening of 

 labour is possible, that, in fact, the digits of the multiplicand 

 can be written down at a steady pace without any auxiliary 

 figuring at all. This is what was actually done in Mr. Muir's 

 verification of Pervouchine's first case. With reference to the 

 editorial query as to how the trial divisors came to be thought of 

 Mr. Muir refers to the Turin Transactions for the present year, 

 M-here there is a paper by M. E. Lucas, which almost entitles 

 him to the merit of being a sharer in the discovery. 



The excavations made in Carniola under the direction of Herr 

 von Hochsfatter, on spots of palKontological and prehistoric! 

 interest, have hitherto been crowned with every success. The 

 Kreuzberg Cave, near Laas, in the district of Zirknitz, proved to 

 be an exceedingly interesting bear cave. The investigations 

 made in this district, at St. Michael, near Adelsberg, and at 

 Klenke, near Waatsch, have furnished undeniable proofs of the 

 existence of prehistoric colonies and burial grounds at these 

 places. Another interesting discovery has just been made at the 

 Laibacher Moor, the well-known pile-dwelling ground. A peat 

 digger found six silver coins of the size of a florin, which all 

 bear the inscription of the Roman Emperor, Augustus Claudius. 

 The discovery has been secured for scientific purposes. 



The Paris Academy of Arts has recently acquired an Egyptian 

 papyrus which is particularly remarkable on account of its reputed 

 age, which is estimated at over 4,000 years. It is perfectly pre- 

 served ; its height is 8-30 metres, and its width 43 centimetres. 



