March 28, 1878] 



NATURE 



423 



in music and one on Arpeggio, by Mr. Franklin Taylor ; 

 an interesting account of the Acad]6mie de Musiquf, 

 by Mr. John HuUah ; an excellent little treatise on 

 Accent in music, with abundant musical examples, by 

 Mr. Ebenezer Prout ; another on Accents in plam song, 

 by the Rev. Thomas Helmore ; instructions as to Accom- 

 paniment, by Mr. Hopkins, of the Temple, supplemented 

 by another article on Additional Accompaniments, 

 by Mr. Prout ; ^olian Harp is from the pen of Mr. 

 Hipkins ; Anthem is given by Dr. Monk, of York ; 

 Arrangement, by Mr. Hubert Parry; Bagpipe, by the 

 writer of this notice. In the biographical department, 

 which is especially full, a long and exhaustive account of 

 the Bach family, by Herr Maczewski of Kaiserslautern, 

 stands foremost. There are also interesting notices of 

 Adolphe Adam and of Auber, by Mr. Franz Hueffer ; of 

 many Italian composers, by Mr. Edward H. Pember, Q.C., 

 of Dr. Arne, and of Attwood, by Mr. Husk, Librarian 

 of the Sacred Harmonic Society ; of Dr. Arnold, and 

 a sympathetic biography of Michael Balfe, by the late 

 Dr. Rimbault. Sir Frederic Ouseley and the Editor 

 contribute several smaller notices. The names of English 

 musicians appear to have received especial attention. 



There can be no hesitation in saying that the work 

 just commenced promises to fill a gap in English biblio- 

 graphy, and that it furnishes excellent material for refer- 

 ence. Besides this, it presents the collateral advantage 

 of offering a charming combination of amusement and 

 instruction for desultory reading in the many horce 

 subsecivcB which occur even in the lives of the most busy. 



W. H. Stone 



OUR BOOK SHELF 

 Pioneering in South Brazil. Three Years of Forest and 

 Prairie Life ifi the Province of Parana. By Thomas 

 P. Biggs-Wither. Two vols. With Map and Illus- 

 trations. (London: John Murray, 1878.) 

 Mr. Biggs-Wither has written two volumes of genuine 

 and varied interest and much instruction, as a result of 

 his three years' work in a little-known region of South 

 Brazil. He went out as one of an engineering party to 

 open up a road between the Atlantic and Pacific, and he 

 traversed much of the country on the banks of the rivers 

 Ivahy and Tibagy, tributaries of the Parand. Much of 

 his time was spent in the forests of this region, virtually 

 unexplored, and presenting a splendid field for any enter- 

 prising naturalist. Mr. Wither is an excellent observer, 

 and his book abounds with information on the natives, 

 the natural history, and physical geography of the region. 

 He met with many adventures, and suffered much from 

 heat and insects, but altogether he seems to have had a 

 thoroughly enjoyable time of it. He writes throughout 

 in an attractive and simple style, and his work must be 

 regarded as an important contribution to a knowledge of 

 the luxuriant region with which it deals. 



LETTERS TO THE EDITOR 

 [The Editor does not hold himself responsible for opinions expressed 

 by his correspondents. Neither can he undertake to return, 

 or to correspond with the writers of, rejected manuscripts. 

 No notice is taken of anonymous communications, 

 [The Editor urgently requests correspondents to keep their letters at 

 short as possible. The pressure on his space is so great that it 

 is impossible otherwise to ensure the appearance even of com- 

 tnunications containing interesting and novel fctctsi\ 



The Phonograph 



We shall be much obliged if you will allow us to draw the 

 attention of your readers to a curious fact which the phonograph 



has allowed us to prove, and which we announced last Monday at 

 a meeting of the Royal Society of Edinburgh. We have seen no 

 mention of the fact elsewhere. 



Not only are vowels unaltered by being spoken backwards, 

 but the same fact is true of consonants. Whether the pulsations 

 of air be made in a given order or in the reverse order the ear 

 accepts the sound as indicating the same letter. This is true of 

 all the simple vowel sounds and of all the simple consonant 

 sounds, including of course several combinations which in English 

 are spelt with two letters, as th or ng, but which are really 

 simple consonants. 



We tried the experiment on single pairs of syllables separated 

 by a single consonant, as ada, aha, aja, ete. A person coming 

 from outside and ignorant of what consonant had been spoken 

 was able to identify the consonants quite as well backwards as 

 forwards. The chief difficulty was found in distinguishing a_ffa 

 from assa. 



We find that this peculiarity is not limited to consonants 

 between vowels, but that ab said backwards becomes ba. We 

 have here a standard as to what does really constitute a single 

 letter or element of articulate speech ; it is any one reversible 

 part. Your readers who possess a phonograph may most easily 

 verify this observation by saying a word backwards, and 

 hearing the phonograph say it intelligibly for vards ; for instance, 

 ttoshdeesossa produces association beauti'ully. 



We shall be glad to learn whether this fact has been already 

 published, and also whether it was foreseen as a possibility by 

 any writer. Fleeming J en kin 



Edinburgh,^March 25 J. A. EwiNG 



The Age of the Sun's Heat in Relation to Geological 

 Evidence 



1. It is an admitted fact that the age of the sun's heat will 

 not harmonise with the evidence of geology, on the supposition 

 that this heat was solely derived from the approach of matter 

 under the action of gravity. Dr. James Croll, in dealing with 

 this question in a recent number of Nature, ^ has suggested the 

 existence of a previous proper motion in the colliding matter that 

 formed the sun, whereby, in accordance with accepted physical 

 principles, a store of heat adequate for any period might have 

 been provided. However a difficulty is raised here by Dr. Croll, 

 in the Philosophical Magazine (May, 1868), where this question 

 is first dealt with, and as this difficulty would seem on examina- 

 tion not to be insurmountable, I venture to call attention to the 

 subject here, more especially as attendant questions of interest 

 would seem to attach to it. 



2. Of course it is admitted that the age of the sun's heat is the 

 limit to conditions of life on the earth, and the point in question 

 is that if the sun had acquired such a store of heat as geological 

 time would appear to demand, then the sun must have been 

 (owing to the excessive heat) a very extensive nebula, probably 

 extending far beyond the limits of the present solar system, and 

 consequently, that even if such a store of heat had existed in the 

 sun, it would not be available for geological time, since the earth 

 could not then have existed as a separate planet, from the fact 

 that the solar nebula would then have extended beyond the limits 

 of the earth's present orbit. Dr. Croll says (p. 372) : " But if 

 the sun had originally possessed the amount of energy supposed, 

 then his volume would have extended beyond our earth's orbit, 

 and of course our earth could not at that time have existed as a 

 separate planet." This, therefore, puts a difficulty in the way of 

 the sun having possessed such a store of heat as would be avail- 

 able for geological time. The accepted princii.les of Laplace 

 are, of course, admitted here, according to which the ea'-'h 

 originally formed part of the nebulous mass of the sun, and 

 became naturally detached through the rotation of the nebula at 

 its contraction. 



3. Here it seems to have been tacitly assumed (according to 

 the quotations above given) that the present orbit of the earth 

 was its original orbit. Is there, however, any necessity for 

 assuming this ? For in this lies all the difficulty. Are we not 

 rather warranted in inferring from accepted principles that the 

 present orbit of the earth was not its original orbit. For it is 

 an admitted fact that resisting media (the ether, &c.) exist in 

 space, by which, through friction, the orbits of the planets are 

 gradually becoming contracted, so that they slowly approach the 

 sun. It is a mere question of time, therefore, for the earth to . 

 have come in towards the sun from any distauce, or its original 



* Nature, vol, xvii, p, 206; »[%o Quarioty Journal q/ Science, July, 

 1877 



