Sept. 2i, 1882] 



NATURE 



509 



into or withdrawn from each circuit with as little disturb- 

 ance as possible to the current in that circuit. To do this 

 without the complications of switches or arrangements of 

 binding screws, the very simple plan of terminals, shown 

 in Fig. 3, has been adopted. The ends of the copper 

 strip forming the coil are brought out horizontally behind 

 the instrument, one above the other, with a thin piece of 

 wood between them for insulator. On one end of the 

 leads for attachment to these terminals is a spring clip, 

 formed of two stout strips of copper, one attached to each 

 lead, kept apart for a short distance along their length 

 by a thickish piece of wood, and held in their places 

 by a serving of waxed cord at that place. The 

 ends of the copper strips project beyond the sepa- 

 rating piece of wood about two or three inches, and are 



bent round into similar curves, with their convexities 

 turned towards one another. They have sufficient spring 

 to bring their convex portions into contact, but they are 

 held together at that place by a stout india-rubber band 

 passed round a groove in the edges of the two semicircular 

 pieces soldered on the backs of the strips. The points, 

 however, of the strips are a little distance apart. If, now, 

 the clip just described be pushed over the terminals of 

 the coil, the jaws of the clip will be separated, but before 

 separation takes place each of them has come into 

 contact with a terminal of the coil. Hence if the 

 leads form part of a galvanic circuit, the current, 

 before the galvanometer is attached, passes from 

 one lead to the other across the jaws of the clips, and 

 after these have been separated, through the galvanometer 



coil ; and it is plain that no cessation of the current, and 

 in practical cases only an infinitesimal disturbance can 

 be caused by introducing the galvanometer. Sparks 

 are thus altogether avoided, and the galvanometer is 

 included in the circuit by a single simple and sure opera- 

 tion. When the leads are withdrawn from the coil- 

 terminals the action is simply the reverse, the jaws of the 

 clip have come together at their convexities before the 

 terminals of the coil have lost contact with them. 



In practice two stout wires which have one pair of ends 

 attached to one of these spring clips are included in each 

 circuit, the current in which is to be measured by the 

 galvanometer. The instrument is placed with its leads 

 attached to its terminals in a convenient position, so that 

 the free end of the leads may reach easily the spring clips 



of all the circuits. The terminals at that end are 

 similar to those of the galvanometer. They can 

 therefore be pushed in between the jaws of each 

 clip to allow the current to be read off, and with- 

 drawn without disturbing the current in the circuit. The 

 leads are shown attached at one end by their spring clip 

 to the galvanometer, and at the other end to a spring clip 

 supposed included by means of the two straight pieces_of 

 wire in a galvanic circuit. 



This arrangement is exceedingly useful for a great 

 number of purposes, as for example for measuring the cur- 

 rents charging secondary cells, or flowing through the 

 various parts of an electric lighting circuit, or for measur- 

 ing the whole current sent into the circuit by the dynamo 

 or generator. Andrew Gray 



NOTES 



The German Association began its proceedings on Monday 

 at Eisenach, when Prof. Haeckel delivered a lecture on the inter- 

 pretation of nature by Darwin, Goethe, and Lamarck. The 

 attendance at the meeting amounted to about iooo. 



The autumn meeting of the Iron and Steel Institute was 

 opened on Tuesday at Vienna in the great hall of the Vienna 

 •Ingenieur und Architekten Verein. In the absence of the 

 president, Mr. Josiah Smith, the vice-president of the Institute, 

 Mr. I. Lowthian Bell, took the chair. The British and other 

 foreign guests were then welcomed, in the name of the Govern- 

 ment, by Baron Possinger, the 'Governor of the province of 

 Lower Austria, and in the name of the city by the burgomaster. 

 Mr. Bernhard Samuelson, M.P., of Banbury, Mas chosen presi- 

 dent of the Institute for the next two years. The place of next 

 year's Congress it was decided should be London. The Congress 

 next proceeded with the reading of the papers set down for the 

 day. After this work was concluded, the Members were con- 



veyed by steamer down the Danube to inspect the works which 

 have been commenced by the Vienna Corporation for improving 

 the navigation of the river. Thence the guests were taken to 

 Nussdorf, and proceeded to the top of the Kahlenberg, a hill in 

 the vicinity. The first day was wound up by a banquet, at 

 which the guests were entertained by the municipal authorities 

 of Vienna. The present is the fourth meeting which the Insti- 

 tute has held upon the Continent, it having met at Liege in 

 1873, at Paris in 1878, and at Dusseldorf in 18S0. The number 

 of guests from abroad is nearly three hundred. They include 

 not only Members of the English Institute, but visitors from 

 America, Germany, France, Belgium, Spain, and Russia. The 

 business portion of this autumn's Congress is expected to occupy 

 three days, but fully a week will be spent in excursions and other 

 festivities, and in visits to the chief ironworks and mines of 

 Austria and Hungary. 



M. Barthelemy St. Hilaire has completed the translation 

 of Aristotle's " History of Animals," which will be published 

 shortly by Bailliere, and will extend to four volumes 8vo, 



