290 



♦ KNO\A/^LEDGE ♦ 



[July 1, 1886. 



than the academicians entering into this composite. They 

 are a group selected as a type of the higher American intel- 

 ligence in the field of abstract science, all but one or two 

 being of American birth, and nearly all being of American 

 ancestry for several generations. The faces give to me an 

 idea of perfect efjuilibrium, of marked intelligence, and, 

 what must be inseparable from the latter in a scientific 

 investigator, of imaginativene.ss. The expression of absolute 

 repose is doubtlfss due to the complete neutrality of the 

 portraits. 



" Fig. 3 contains eighteen naturalists and thirteen mathe- 

 maticians, whose average age is about .52 years. Fig. 1 

 contains twelve mathematicians, including both a.stronomei's 

 and physicists, whose average age is aliout .51^ yeais. Fig. 

 2 is a composite of si.xteen naturalists, including seven 

 biologists, three chemists, and six geologists, with an average 

 age of about 52.'- years. 



'• I may mention, as perhaps only a remarkable coincidence, 

 that the positives of the mathematicians, and al.so of the 

 thirty-one academicians, suggested to me at once forcibly the 

 face of a member of the Acadeuiy who belongs to a fomily of 

 mathematicians, but who happened not to be among the 

 sitters for the composite. In the prints this resemblance is 

 less strong, but in these it was observed quite independently 

 by many members of the Academy. So, also, in the positive 

 of the naturalists, the face suggested, also quite indepen- 

 dently to myself and many others, was that of a very eminent 

 naturalist, deceased several years before the sitting for this 

 composite. 



" There is given also a composite (fig. 4) of a ditTerently 

 .selected group. It is of twenty six members of the corps of 

 the northern transcontinental survey — an organisation of 

 which I had charge, and the oliject of which was an economic 

 survey of the North-Western Territoiaes. It was a corps of 

 men carefully selected as thoroughly trained in their I'cspec- 

 tive departments of applied geology, topograph)-, and chemis- 

 try, and having the phyi-i'|ue and energy, as well as intelli- 

 gence, needed to execute such a task in face of many obstacles. 

 The average age of this group was 30 years." 



DRAWING ELLIPSES. 



IIEEE are many ways of drawing ellipses, 

 from the wietched way commonly described 

 as a good way (the string-and-pin method) 

 to very complicated though very exact 

 methods. Perhaps there is no way much 

 simpler than that illustrated in the figure 

 on page 291 (fig. 1). It needs no explana- 

 tion. Two equal s^'ries of equidistant, circles are described 

 around each focus, and the intersections of the successire 

 circles (taken increasingly) of one set, with the successive 

 circles (taken decreai-iugly ) of the other set, give an ellipse. 

 To determine an ellipse having given foci, and a given 

 minor axis, one has only to take that particular ellipse, of 

 .several given by the construction, which passes through the 

 ends of the desired minor axis. (Or the major axis, if we 

 prefer it, may be used to determine the ellipse.) Of course, 

 it is quite easy to take the radii of our circles so that two 

 equal circles around the foci shall intersect at extremities of 

 any indicated minor axis, or, if we prefer it, two ciicles 

 .around the foci may intersect at any desired distance from 

 either focus to determine an end of the major .axis: after that 

 taking equal divisions along the major axis, produced if 

 necess.ary, we get all other radii. Fig. 2 illustrates a similar 

 method for drawing any desired hyperbola, 



Natural Causes and Supernatural Seemincjs. By Henry 

 Maudsley, M.D. (London : Kegan Paul, Trench, & Co. 

 1886.) Dr. Maudsley remarks that " a really new I'eflection 

 is probably .as rare and doubtful an event as a new virtue, 

 or a new vice, or a new di.sease." But if, in agreement with 

 this, we abstain from .speaking of his book as original, we 

 may none the less assess it as one of the wisest and most 

 thoughtful books of our time, and not unneeded. Its object 

 is to examine how far the great mass of supernatural beliefs 

 which have persisted from the lower cultiu'e till now, and 

 which are still held by an overwhelmingmajority of civilised 

 mankind, are I'eferable to causes which were concomitant 

 with man's mental development, and are operative still. For 

 in the degree that these beliefs are brought under the law of 

 causation — in other words, accounted for — they are removed 

 from the ever-contracting area of the unexplained, and 

 divested of their artificial importance. Dr. Maud.sley submits 

 these " seemings" to scientific inquiry, seeking for the modes 

 of their origin and growth within the region of human ex- 

 perience, and narrowing them within the sphere of medical 

 psychology. Discai-ding theories of revelation, spiritual 

 illumination, and other assumed supermundane sources of 

 knowledge, the author finds sufficing causes in the operations 

 of the mind both in health and disease. In the one there is 

 the defective and false reasoning due to man's long un- 

 corrected sense -perceptions, and to the uncurbed play of 

 imagination ; in the other there are the h.allucinations, 

 visions, epidemic delusions, and other abnormal states which 

 are the ]noduct of bodily exhaustion and unsound mental 

 .action. Then there are the ecstatic conditions which in the 

 lives of the saints and the confessions of morbid natures aie 

 referred to the direct action of the divine on the human, 

 but which are really the product of sp.asmodic nervous 

 action or of indigestion. As Hood says of such folks, " they 

 think they're pious when they're only bilious." The earlier 

 chapters furnish an interesting analysis, aided by apposite 

 illustrations, of the causes of fallacious reasoning as to super- 

 natural existences through coincidences due to apparent 

 answers to pr.ayer, to fulfilment of dreams, to good or ill 

 luck on certain days, to distorted or false observations, and 

 also through the innate tendency of the human mind to find 

 a supernatural cau.se for whatever it cannot understand, as 

 notably illustrated in the belief in witchcraft which, sup- 

 ]3orted by the authority of the Old Testament and the reason- 

 ing of distingui.shed doctors and jurists, lingeied amongst us 

 far into the last century. From these the author pas.ses to 

 the use and misuse of the imagination. That which under 

 wholesome restraint has been the incentive and initiative of 

 progress, of enterprise, of inquiry, of noble ideals, has, un- 

 restricted, led the enthnsia.st and the dreamer into the 

 engulfing quicksands of theories. And Dr. Maudsley, there- 

 fore, looks forward to a time when this purposeless waste 

 shall be stopped, and the imagination, abstaining from soar- 

 ing where it vainly beats the air, shall gain a hundredfold 

 in power and in service to m.an " in working soberly to 

 definite ends within the domain of sense and thought." 

 The general lesson of the book may be gathered from 

 this extract : — 



Not by standing out of nature in the ecstacy of a rapt and over" 

 str.ained idealism of any sort, but by large and close and faithful 

 converse with nature .and human nature in all their moods, aspects, 

 and relations, is the solid basis of fruitful ideals and the soundest 

 mental development laid. The endeavour to stimulate and strain 

 any mental function to an activity beyond the reach and need of 

 a physical correlate in external nature, and to give it an independent 

 value, is certainly an endeavour to go directly contrary to tlie sol;>er 

 and salutary method by which solid human development has taken 

 place in the past, and is taking place in the present. 



