August 12, 1897] 



NATURE 



343 



which overlap, and which, as shown in the cut, are tied tfigether 

 at a point about 4 centimetres above each of the balls. No ball can 

 be laterally displaced without tending to drag its neighbour also ; 

 so that a shearing stress is transmitted along the line of Iwlls. As 

 Reynolds showed twenty years ago, the velocity of propagation 

 of the wave-front differs from that of the group of waves owing 

 to the continual dying away of the amplitude of the advancing 

 waves. This effect, due to the inertia of the medium, is of 

 course equivalent to the presence of dispersion in the medium, 

 waves of different frequencies being propagated with slightly 

 different velocities. So far, therefore, as Prof Fitzgerald re- 

 marked when the model was exhibited, it illustrates the pro- 

 pagation of the wave in a refracting medium rather than in the 

 ether of space. The waves in the model travel quite slowly ; 

 and there is a fascination in watching their progress along the 

 row of balls, until they arrive at the resonator and set it into re- 

 sponsive vibration. There is, of course, no attempt made here 

 to represent the magnetic part of the electromagnetic wave, at 

 right angles to the electrostatic part ; the mechanical displace- 

 ments in the model corresponding to the electrostatic displace- 

 ments of the Hertzian wave. A row of inter-connected pen- 

 dulums such as this affords a means of illustrating many points 

 in physics. For many purposes the elaborate system of sus- 

 pension by strings may be replaced by a continuous fabric. 

 Thus, for example, a piece of netting, hung on hooks from a 

 horizontal rail, and ending below in a short fringe, with leaden 

 beads on the fringe-tips, will also serve to illustrate the pro- 

 pagation of a transverse wave. The structure adopted absolutely 

 refuses to transmit longitudinal disturbances ; there being no 

 compressional elasticity between the balls to propagate a 

 ■longitudinal wave. Silvanus P. Thompson. 



Blackbird's Nest appropriated by a White Wagtail. 

 I SEE in Nature of July 15 (p. 248), a letter to the effect that 

 a wagtail had appropriated a blackbird's nest. I beg to state 

 that on June 12 I had the good fortune to find a similar nest at 

 Coburg in Germany. There was a blackbird's nest behind a 

 .summer-house in the garden where I was staying, against the 

 wall about 16 feet from the ground. The white wagtail had 

 lined it with moss, hair, and thread, and laid six eggs in it, 

 which, together with the ne.st, are now in my collection. The 

 gardener and myself both identified the bird. 



G. W. DE P. Nicholson. 

 Jesus College, Cambridge, July 27. 



THE ROYAL SOCIETY AND ITS 

 HAND-BOOKS.^ 

 TT is with most corporations, and especially with an 

 J- ancient corporation like the Royal Society, a matter 

 of some practical moment to maintain continuity of life 

 -ind action, and it is always interesting to record that 

 continuity. The "Record of the Royal Society" has 

 this, apparently, as its aim. The " Year-book of the 

 Royal Society," published some few months ago, con- 

 tains, so the preface to the " Record " informs us, in- 

 formation which is liable to change, and the "Year- 

 book " will accordingly be issued annually ; but " the 

 'Record' contains information, largely historical, such 

 as will not need more than slight additions from time to 

 time," and it is intended therefore to issue new editions 

 of this only at .intervals of a few years, as may be found 

 desirable. 



Reference to the "Year-book," a copy of which has 

 been sent to us with the " Record," shows that it contains 

 such matters as a table of the meetings for the Session, 

 a list of the Fellows, lists of the Council and Committees, 

 the Statutes, standing orders, and regulations for various 

 occasions, the Society's balance-sheet, schedule of estates 

 and property, and much other matter which is strictly 

 md exclusively of official utility and interest. But the 

 • Record," although it has been officially prepared, as we 

 learn from the preface, by the secretaries, aided by Mr. 

 H. Rix, the late assistant secretary, and is in the main 



• " The Record of the Royal Society of London," 1897, No. i. " Vear- 

 !)ook of the Royal Society of London," 1896-97, No. i. 



NO. 1450 VOL. 56] 



a hand-book of an official sort intended for official pur- 

 poses, contains, nevertheless, so much that is historical— 

 so much, let us add, that is quaint and antique in flavour — 

 that it has very considerable general interest. 



The volume opens with an " Account of the Founda- 

 tion and Early History of the Royal Society," in which 

 Sprat's, Thompson's and Weld's histories have been used 

 to some extent, but in which much use has also clearly 

 been made of the original MSS. upon which those 

 histories are based. The story has often been told how, 

 about the year 1645, "divers worthy persons, inquisitive 

 into natural philosophy and other parts of human learn- 

 ing," used to meet in London, sometimes at Dr. God- 

 dard's lodgings in Wood Street, sometimes at the " Bull 

 Head" in Cheapside, and, in term-time, at Gresham 

 College ; how, about 1648 or 1649, some of this company 

 removed to Oxford, where they founded the Philosophical 

 Society of Oxford, while the Londoners continued their 

 meetings, usually at Gresham College, until the famous 

 gathering of November 28, 1660, when, after Mr. Wren's 

 lecture, the company being withdrawn for " mutuall con- 

 verse," " amongst other matters that were discoursed of, 

 something was ofTered about a designe of founding a 

 Colledge for the promoting of Physico-Mathematicall Ex- 

 perimentall Learning." In the present "Account of the 

 Foundation" the steps are traced by which this meeting 

 led to the foundation of the Royal Society, the Charter of 

 Incorporation passing the Great Seal on July 15, 1662, 

 for which grace on the 29th of that month the President, 

 Council, and Fellows went to Whitehall and returned 

 their thanks to his Majesty. 



The compilers of this "Account" lay stress upon the 

 fact that in the infancy of the Society one inost im- 

 portant feature of a meeting was the performing of 

 experiments before the members. " The experiment 

 was performed for and by itself, and not merely, as now, 

 in illustration of a ' paper communicated.' Papers were 

 read then as now ; but the reading of such papers formed 

 only a part, and by no means a great part, of the business 

 of the meeting." An e.xample of one of these early meet- 

 ings is given, and as it does not appear in Weld's 

 "History," and is a very interesting glimpse of seven- 

 teenth century science, it may be worth printing it here 

 in full. 



September 10///, 1662. 



" Mersennus, his account of the tenacity of cylindrical! 

 bodies was read by Mr. Croone, to whome the prosecu- 

 tion of that matter by consulting Galiheo, was referred 

 when the translation of that Italian treatise wherein he 

 handleth of this subject shall bee printed. 



" It was order'd, that, at the next meeting Experiments 

 should bee made with wires of severall matters of ye 

 same size, silver, copper, iron, &:c., to see what weight 

 will breake them ; the curator is Mr. Croone. 



"The reading of the french manuscript brought in by 

 Sr. Robert Moray about taking heights and distances by 

 catoptricks was differred till the description of the in- 

 strument should come. 



" Dr. Goddard made an experiment concerning the 

 force that presseth the aire into lesse dimensions ; and it 

 was found, that twelve ounces did contract o\ part of Aire. 

 The quantity of Air is wanting. 



"My Lord Brouncker was desired to send his Glass to 

 Dr. Goddard, to make further experiments about the 

 force of pressing aire into less dimensions. 



"Dr. Wren was put in mind to prosecute Mr. Rook's 

 observations concerning the motions of the satellites of 

 Jupiter. 



" Dr. Charleton read an Essay of his, concerning the 

 velocity of sounds, direct and reflexe, and was desired to 

 prosecute this matter ; and to bring his discourse again 

 next day to bee enter'd. 



" Dr. Goddard made the Experiment to show how 

 much aire a man's lungs may liolJ, by sucking up water 



