yune 1 6, 1881] 



NA TURE 



HI 



written bis papers without having read Boole's "Laws of 

 Thought." I linewthat he was very anxious that the fact should 

 be known, and I called attention to it. I could not state it as a 

 fact known to me. His own assurance was the only ground I 

 had, or could have, to go upon, and in assigning this it never 

 occurred to me to doubt his statement, or to think that I was 

 suggesting doubts to others. 



As regards my half humorous suggestion that an attitude of 

 slight social repression was desirable towards novelties of mere 

 notation — not tov\ ards new conceptions or methods — -I feel sure 

 that almost every one who has not a private scheme of his own 

 to protect will agree with me. Few things can be more | er- 

 plexing to students of any subject than to lind one author after 

 another making use of a new notation to express old results 

 (I mean no special reference to Mr. MacCoU here, who does not 

 seem to me one of the worst offenders in this way). At the time 

 of writing my "Symbolic Logic"! had between twenty and 

 thirty such schemes before me. Some of these, of course, 

 express really distinct conceptions, or effect improvements in 

 ])rocedure, but most of them do not ; we find half-a dozen 

 different signs standing for the same meaning, and half-a-dozen 

 different meanings assigned to the same sign. I cannot but 

 think that much of this confusion would be avoided if the 

 various authors would take the trouble to inquire what had been 

 already written upon their subject. The only " repres ion " I 

 should like to see introduced consists in the remonstrances of 

 reviewers and students generally against the mere tu' stitution of 

 a new symbol for one which was already in u.e for expressing 

 precisely the same process or conception. So far from \\ ishing 

 to discourage any attempts to improve on the results of Boole 

 and others, I rejoice to see them, and think that Mr. MacCoU 

 himself has done some good work in this way. It would have 

 been better still if he had not disfigured it by a notation which I 

 think makes him regard his results as more original than they 

 really are. 



I need not seriously discuss those parts of Mr. MacColl's letter 

 which give his opinion as to the impression which will be pro- 

 duced in other persons by a perusal of my book, and his 

 "imprfssion" that he has "somewhere seen Mr. Venn quoted 

 as holding an opinion very much at variance w ith " a statement 

 which he misquotes." (By the way, I heartily agree with his 

 " protect against that >piritcf criticism which would offer two 

 or three chipped bricks as a fair specimen of a hou?e," &c., and 

 think the chipping of the bricks a happy turn.) The rest of his 

 letter contains criticisms upon my conclusions on a variety of 

 rather intricate speculative questions. Having stated my own 

 views as fully and accurately as I conveniently could only a few 

 weeks ago, in a systematic work, I really n.ust decline to be 

 drawn into repeating them again, in a conden: ed form, in the 

 columns of a scientific journal, even if the editor would consent 

 to accept them. J.Venn 



Cambridge, June 12 



Telephones in New Zealand, cSc. 



Observing 5 our paragraph on thisFubject in Nature, vol. 

 xxiv. p. 88, it occurs to me that the following may be of 

 interest : — When in Wellington and Dunedin, N.Z., at the end of 

 December last, my opinion was asked by the Government Tele- 

 graphic officials there upon a pair of ordinary "Edison-Bell 

 Telephones " (ni>t Edison bdltdephones, as they are too frequently 

 called) whicli they had just received from the United States for 

 purposes of experiment. A careful trial under various conditions 

 showed me that they were very good average instruments of 

 ordinary delicacy, such as I had seen hundreds of previously in 

 England and the States. 



With these instruments, however, Dr. Lemon, the Superin- 

 tendent of the Postal and Telegraph Service, was able to con- 

 verse clearly between Wellington and Napier, over an ordinary 

 land line 232 miles in length, while battery currents were passing 

 over the wiies on the same posts. 



In New Zealand, Telegraphic communication is, and Telephonic 

 communication will be, entirely in the hands of the Government. 

 In Melbourne the telephone-exchange is worked by a private 

 company, but the erection and maintenance of wires is carried out 

 by the Vict.irian Government at the annual rate of 5/. per sub- 



' What I spoke of was " those problems in Probability which B. ole justly 

 regarded as the crowning triumph of his system." What Mr. MacC.ll puts 

 betweeil inverted comraas is that Booie "justly regarded his problems in 

 Probability as the crowning triumph of his system," and challenges me to 

 say whether or not I agree with Boole's solution of a certain well-known 

 example. This considerably distorts the meaning of what I said. 



scriber. In Sydney, I regret to say, nothing was being done in 

 this matter. In Honolulu I found (last January) telephonic 

 communication all over the town, but no telegraphs at all. The 

 King of the Sandwich Islands however. Alii Kalakaua, who is 

 shortly expected in England, tdd me that he greatly needed sub- 

 marine cables between the vaiious islands. On my return to 

 England I had the pleasure of sending to Sydney materials for a 

 private telephonic line on sugar plantations in the Fiji Islands, 

 and my friend Mr. Frederick Cobb, manager of the Falkland 

 Islands Company, tells me that the line he took out there at my 

 suggestion is a great success. 



At Wellington, where the central N.Z. telegraph office is, I 

 was very much struck by the extreme ease with which duplex 

 circuits were worked. Dr. Lemon informed ir,e that it was 

 scarcely necessary to alter the resistances once a W'cek. He 

 showed me a simple little carbon rheostat of his own invention 

 which appeared to answer admirably ; it consisted essentially of 

 two pieces of carbon, the closeness of whose contact was 

 regulated by a screw. 



On my way home I paid a hm-ried visit to the central office of 

 the Western Union Telegraph Company in New York (just at 

 the critical time of the absorption by it of the other two 

 companies and the consequent creation of a monopoly), and was 

 greatly surprised to see the extent to which the 16,000 cells in 

 the battery room were being replaced by Siemens's dynamo- 

 machines. I was told that one of them would "driVe" about 

 fifty wires, and was shown a number of plaster-of-paris cylinders, 

 about five inches long and one inch diameter, which were put 

 into circuit to diminish, when necessary, the intensity of the 

 current. It may be remembered that as a ru'e American lir.es 

 are less perfectly insulated than ours, and hence require stronger 

 currents. Wm. Lant Carpenter 



6, York Buildings, Weymouth, June I 



Implements at Acton 



Mr. Perceval's letter in Nature, vol. xxiv. p. loi, is an 

 interesting one, but the occurrence of Neolithic implements at 

 and near Acton has been kno«n (if not published) for many- 

 years past. In the Pitt-Rivers' collection may be seen Neolithic 

 scrapers and flakes from the Acton di.-trict. I have found 

 Neolithic stones in the neighbourhood of Acton and Willesden 

 for many years past ; and only a few weeks ago I picked up a 

 beautiful and perfect knife of black flint made from a large flake, 

 five and a half inches long, and one and three quarler inches 

 wide, in the field on the east of Acton Station of the North 

 London Railway. Many of the Neolithic flints from this posi- 

 tion are white. A considerable lumber of Neolithic implements 

 and flakes have at different times been dredged up from the 

 Thames to the West of London, and some of the e have 

 been quite recently exhibited. I do not attach imporlance to 

 the quartzile pebble, as pebbles of quartzite are extremely 

 common in the glacial deposits at the North of London, and 

 very common in the gr,-:vels of the Thames and its northern 

 tributaries. They also occur in silu at the north of Willesden. 



Will Mr. Perceval kiudly fuinish the heights at the Hammer- 

 smith position, and say \\helher he is positive that the gravel 

 he has in view was dug on the spot, and whether the imple- 

 ments occur there (as his letter implies) in "remarkable abund- 

 ance " ? I have repeatedly examined the low gravels about 

 Hammersmith, Fulham, and Chelea, but with no result. For 

 more than three years I have never missed an opportunity of 

 looking over the low gravels belonging to the^e places, together 

 with the positions at West Brompton and Kensington, w here 

 thousands of tons of gravel have been excavated. My result 

 has been one dubious flake, probably wa>hed down from one of 

 the higher terraces. I however have beard of two Palaiflithic 

 implements having been found — one at Kensingtc^n and the 

 other at West Brompton — but whether from the local gravel or 

 not I am uncertain. 



I by no means wish to imply that because I have been unable 

 to find implements in the lower gravels therefore some one else 

 may not have found them. Some one may have been always 

 before me and picked them up, or I may have constantly looked 

 over unproductive patches. 



The places mentioned by Mr. Perceval are, it must be remem- 

 bered, frequently ballasted \\ith gravel br. ught from a distance 

 by the Thames, by the Grand Junction Canal, ard by the Great 

 Western Railway. I know of at least five different localities 

 whence the Acton and Hamii.ersmith gravel is brought, one 



