November 15, 19C0J 



NATURE 



61 



additional matter ; to Dr. P. Matschie's " Geographische 

 Fragen aus der Saugethierkunde," published in 1896 ; to 

 Mr. R. I. Pocock's "Geographical Distribution of the 

 Arachnida," which appeared in Natural Science for 1899 5 

 to Dr. Max Weber's paper on the " Origin of the Fauna 

 of Celebes" {Ann. Nat. Hist., 1899); and, lastly, to 

 Prof. H. F. Osborn's " Correlation between Tertiary 

 Mammal Horizons of Europe and America" {Ann. 

 N. York Acad., 1900). In several of these papers special 

 stress is laid on the evidences of connection between the 

 faunas of the southern continents which have been 

 steadily accumulating during the last few years ; while, 

 as already mentioned, Prof. Osborn's communication is 

 notable on account of his theory as to the indigenous 

 origin of the African fauna. In another part of the 

 world a most important change in the limits of two 

 geographical regions has been suggested (first by Mr. 

 Sclater and then by Dr. Weber), by the transference of 

 Celebes from the Australian to the Oriental region. If 

 this change, together with a similar transference in the 

 case of Bali and Lombok, which has been advocated 

 (partly on the suggestion of Dr. Blanford) by the 

 present writer, be generally adopted (and it seems inevit- 

 able), we have to bid farewell for ever to the almost 

 classic " Wallace's Line," as being one of those hypo- 

 theses which, although useful in their day, were not 

 destined to immortality. R. L. 



INSTRUMENTS OF PRECISION AT THE 

 PARIS EXHIBITION. 



"AT the commencement of the nineteenth century, the 

 -^~^ French and English makers of scientific instru- 

 nients were far in advance of the Germans. True, the 

 eighteenth century knew of prominent mechanicians . . . 

 yet the French and English makers took the lead so as 

 almost to supply the world's entire demand in scientific 

 instruments. This predominance had the further con- 

 sequence of causing young Germans to emigrate to 

 France or England in order to thoroughly master their 

 subject. Many a German mechanic of to-day owes to 

 French or English masters a substantial portion of his 

 knowledge. The prominence of the French and English 

 instrument makers was mainly due to the support which, 

 in both countries, the State bestowed upon technical art." 

 ... "In Germany it is only within the last twenty or 

 twenty-five years that the State has espoused the interests 

 of the home industry in scientific instruments ; but such 

 have been the efforts and the results, that her position 

 has, at a blow as it were, changed in favour of 

 Germany." 



These words are taken from the special catalogue of 

 the joint exhibition of German mechanicians and opticians 

 at the Paris Exhibition, which claims, and claims with 

 truth, "that in this department Germany occupies now a 

 foremost position." As to the excellence of this joint ex- 

 hibition, it is difficult to speak too strongly ; rumour 

 says that some, at least, of the judges wished to award 

 it a Grand Prix among the nations. Had the rules of the 

 Exhibition allowed it, such an award would have met with 

 the universal approval of all physicists who have visited 

 Paris. 



Another brief quotation from the preface will explain 

 the position more clearly. "After witnessing," the 

 writers say, "the steady development of our mechanical 

 and optical trade, we cannot but look with gratification 

 upon the practical demonstration, at the Paris Centenary 

 Exhibition, of the flourishing state of the scientific instru- 

 ment trade in Germany ; and a characteristic feature of 

 the latter is the unity of its aims, which is traceable to 

 the history of its development and to its ultimate con- 

 nection with pure science. It appeared, therefore, de- 

 sirable to depart from the usual custom of grouping the 



NO. 1620, VOL. 63] 



exhibits under various firms, and to place them in 

 sections embracing certain classes of instruments, so as 

 to demonstrate on broad lines and, as a whole, within a 

 well-arranged though condensed area, the present 

 position of German mechanical and optical art." 



Accordingly this was done under the auspices of the 

 German Association of Mechanicians and Opticians, and, 

 with the help of the authorities of the Reichsanstalt 

 and of the Standardising Commission, a most remark- 

 able exhibit has been arranged ; a catalogue has been 

 prepared, covering some 250 small quarto pages, well 

 illustrated, with a full account of the various instruments 

 and references to sources of further information. This 

 is published in German, French and English — why the 

 English edition is printed in German type is perhaps 

 somewhat of a mystery— and issued freely to visitors 

 who wish to use it. 



The preface to this catalogue, from which the above 

 extracts are taken, gives an interesting account of the 

 growth of this industry, from which it appears that in 

 the last ten years the annual value of the mstruments 

 exported, including the optical glass used for lenses, 

 has risen from something over 200,000/. to over 700,000/. 



The general exhibition is arranged in ten sections, 

 with various subsections ; the special exhibit of the 

 Reichsanstalt forms an eleventh section to itself In 

 each of these sections or subsections the exhibits of each 

 maker form a class to themselves. 



Thus Section V., optical instruments, has seven sub- 

 divisions. The exhibit of Carl Zeiss, for example, appears 

 in five of these, as well as in Section II., astronomical 

 instruments. By means of the table of contents and list 

 of exhibitors, it is easy for a visitor to find either the 

 apparatus of a special class or the exhibit of a particular 

 firm as he will. 



Section I. contains metrological and standardising 

 apparatus, and here the exhibit of the Normal Aichungs 

 Commission is most striking. The Commission is pre- 

 sided over by a director, and includes, we are told, three 

 Government councillors, twenty-four technical officials, 

 and ten clerks ; the annual expenditure is 8500/. Con- 

 trast this with the staff of our Standards Department, and 

 its expenditure, according to Whitaker, of 2877/. Speci- 

 ally noteworthy, perhaps, among the exhibits of the 

 Aichungs Commission are the model of their great 

 comparator, and the vacuum balance made by Stiickrath 

 for comparing masses from 200 grammes to one kilo- 

 gramme. But a detailed description of the catalogue 

 would take too much space, and would indeed be of no 

 great value to a reader ; the book itself will prove to a 

 physicist a well of useful information ; the exhibit, how- 

 ever, must be seen in its entirety if we wish to realise 

 what our German cousins have done. 



Not that the sight is one which brings great pleasure 

 to an Englishman, and if he moves on to examine the 

 English exhibit his thoughts cannot fail to be very grave. 

 There is nothing which can be compared with the 

 German show ; some well-known firms have won well- 

 deserved prizes ; there are some few interesting pieces 

 of apparatus from South Kensington, and here and there 

 in the electrical department one comes across a case of 

 instruments. For the rest, the visitor will find, not col- 

 lections of scientific apparatus, but small portions — at- 

 tractive portions, it is true, in many cases — of the windows 

 of well-known opticians' shops. As much apparatus as 

 is possible is packed together in a small space, there is 

 much repetition, there is no organisation, there is no 

 attempt to instruct the learner or to attract the man who 

 comes with inquiries with a view to purchase ; English 

 mechanics and opticians have no unity of aim, and their 

 art, with some few exceptions, is but loosely linked to 

 pure science. 



A visitor who visits Paris to look for the most recent 

 forms of scientific apparatus must have the conviction 



