392 



NATURE 



\Scpf.. I?, 1872 



larly employed on such work. Wc are accustomed to 

 quote with pride the old saying, that wherever wood would 

 iloat an English pendant was to be seen, and it is true 

 at the present time, that every sea, well known or slightly 

 known, is visited more or less frequently by our men-of- 

 war. But unfortunately many of these places are roughly 

 surveyed, the coast lines inaccurately laid down, and the 

 positions of the principal dangers doubtful. Here much 

 valuable work can be done by those not surveyors, who have 

 time and are willing to take the opportunities often given 

 them, to improve our knowledge by making a correct sur- 

 vey or verifying the charts of the coasts they may visit. 

 To these Mr. Laughton's book will be exceedingly v.alu- 

 ablc, and though in his introductory chapter the author 

 modestly says that he writes "not for the guidance 

 of surveyors, but for those who know little or nothing at 

 all about it," we are sure that many old surveyors will 

 iind their work easier from having; the principles so clearly 

 brought before them. The work is the more valuable in 

 showing what can be done with the means at -hand on 

 board every vessel, though not especially equipped for the 

 work. The second chapter describes the choice and 

 measurement of the base line, and the methods for de- 

 termining the exact latitude and longitude of the first 

 position. The rules given arc exceedingly clear and 

 simple, and can be readily followed by anyone in tlie 

 habit of using the sextant and artilicial horizon. The 

 hints on the choice and adjustment of the sextant will be 

 found verv useful to every navigator. Mr. Laughton's 

 practical way of dealing with the subject is shown in his 

 sun-o-estion to get an old sextant and let it fall on the deck 

 in "order to acquire a thorough acquaintance with its 

 mechanism in putting it to rights agam. But it is a pity 

 that the description of the instruments should be placed 

 between the rules for the choice and measurement of the 

 base line, indeed it would be better if this chapter were 

 re-arranged. A great deal more might be said on the 

 selection of objects for triangulation, this is a point on 

 which the beginner encounters his greatest difficulty ; 

 some hints also as to the best way of noting angles would 

 be useful, this want is supplied when levelling is treated 

 of. Chapter 111. is devoted to the construction of charts 

 and various projections of the sphere, it is very clear and 

 concise, and will prove valuable not only to the chart- 

 maker, but also to the navigator, who will here gain a 

 clearer knowledge of the plan on which the chart he uses 

 is laid down, than is to be found in most books on navi- 

 gation. We recommend, especially to young surveyors, 

 the method advocated for graduation of charts according 

 to the gnomonic projection, it is more comprehensive and 

 certainly more mathematically correct than the methods 

 usually employed, and we do not remember to have m>t 

 it described in any other work. The part of Chapter IV. 

 relating to the determination of positions is perplexuig, 

 and would with difficulty be understood by an inexperi- 

 enced surveyor, without examples. The author might have 

 well supplemented this part by showing graphically the way 

 of protracting the angles, and finding the points of inter- 

 section. It is not clear why he has omitted from the 

 description of instruments all mention of the protractor, 

 an instrument as essential to the surveyor and navigator 

 as his pair of compasses. The remarks in the last few 

 pages on the " danger angle," or as it was called by old 

 surveyors the " approximative angle," will be found very 

 useful by all navigators, especially those who since the 

 introduction of iron ships have experienced the difficully 

 and uncertainty of determining positions quickly by the 

 compass when the course is changing rapidly. The run- 

 ning survey is ably treated, but we regret there is no 

 illustration of the mode of surveying a harbour ; this is 

 a serious omission, but notwithstanding this, and the 

 want of illustration of the choice of stations and selec- 

 tion of objects, wc can recommend the book as the best 

 out on the subject. 



The Lepidopterist's Guide, intended for the Use of the 

 Young Collector. By H. Ouard Knaggy, .M U , F.L. x 

 .Second Edition, illustrated. (London: Van Voorst.) 

 The want of such a " Guide " as the present was long 

 felt by "young collectors" before the appearance of this 

 book ; but now this want is so well supplied that a second 

 edition has not only been issued, but nearly exhauste<l, 

 and we call attention to it with confiden:e, because, 

 although eminently popular in its style and treatment, it 

 is the work of a practical hand, and is as reliable as it is 

 full and complete. In these days of cheap books it is 

 marvellously cheap, and we are led to wonder how a 

 scientific manual of upwards of 120 pages, closely 

 printed, and copiously illustr.ated, can be produced for ore 

 shilling. Everything that the young collector is likely to 

 require information upon will be found by a little searchmg, 

 which a copious index would greatly facilitate, and which 

 we hope to see appended to a future edition. We have no 

 doubt this Guide will continue to receive the support it so 

 well deserves. C. 



LETTERS TO THE EDITOR 



[ The Editor does not hold himself responsible for opinions expressed 

 by his correspondents. No notice is taken of anonymous 

 cotnmunieations. ] 



The Variation in Outline of American " Flint " 

 Arrow-heads 



I FIND, .after a careful perusal of the sixteenth chapter of Mr. 

 Evans's magnilicent work on British Stone Implements — on 

 javelin and arrow-lieads — that he has considered the American 

 forms far more uniform, less varied in outline than tliey realiy 

 are. I am familiar with many collections made at distant par's 

 of the Union, and liave an immense assortment of my own col- 

 lecting now in the Museum of the Peabody Academy, at Salem, 

 Miss. In these several collections is every form that Mr. Evans 

 has figured, and several that he has not mentioned. 



On page 362 of Mr. Evans's work, I find the author assert- 

 ing as a prev.ailing type, " that with a notch at the base on either 

 side." While this form unquestionably is very common, it can- 

 not be considered as the " prevailing" one, inasmuch as several 

 distinct patterns equal it in numbers found, and some exceed it, 

 as those that "have merely a central tang, with little or no at- 

 tempt at barbs. " A second statement of Mr. Evans strikes me as 

 very remarkable. He says, "the leaf-shaped form is very rare." 

 This is a very great error. In any locality where arrow-points 

 are to be found at all, they are always to be met with ; and I 

 have gathered scores of them that for symmetry far excel any of 

 the figures given by Mr. Evans. 



Nor can I admit the correctness of Mr. Evans's assertion 

 concerning arrow-points, that " for the most part the chipping is 

 but rough, as the material, which is usually chert, hornstone, or 

 even quartz, does not readily lend itself to fine work." I 

 believe no arrow-points have ever been discovered that can 

 exceed, in beauty of finish, those I have myself gathered 

 from the fields and meadows of central New Jersey. .And I 

 am the more surprised at Mr. Evans's remarks, inasmuch as the 

 specimens I have found, that have been wrought from while or 

 rose quartz, are remarkable for the smooth surfaces and sharp 

 edges they present. .Sii, too, of our jasper and hornstone speci- 

 mens. Remarkably diversified in form, uniformly well fnislied, 

 I they strike the beholder with astonishment, when the "intracta- 

 bihty " of the material is recognised. I have seen but few 

 specimens of arrow-points not found in the United States ; but 

 judging from them and the illustrations of Mr. Evans's woik, I 

 unhesitatingly assert, that although we have no convenient Hmt 

 in New Jersey or near it — Prof T. A. Conrad has discovered 

 true flint and chalk in Colorado — we have, in the jasper, chert, 

 hornstone, quartz, and slate arrow-heads, examples of such 

 weapons, as are in no wise inferior to those of Europe in beauty 

 of finish, or less diversified in the various so-called "types." 



Mr. Evans seems to have based most of his impressions con- 

 cerning our antiquities upon Schoolcroft's ponderous tomes, 

 which present little or noihing of value, of our "antiquities," 

 whatever may be their reliability as concerning the " Indians," at 

 the time when the volumes were compiled. 



