May 1, 1885.] 



♦ KNOWLEDGE ♦ 



365 



while observing the plates, the rings of the convex plates 

 will advance outwoid, those of the concave inward. It 

 may be asked by the meohaniciau, Can this method be used 

 for testing our surface plates 1 I answer, that I have found 

 the scraped surface of iron bright enough to test by sodium 

 light. My assistant in the machine work scraped three 

 8 in, plates that were tested by this method aud found 

 to be very excellent, though it must be evident that a 

 single cut of the scraper would change the spot over which 

 it passed so much as t j entirely change the appearance 

 there, but I found I could use the test to get the general 

 outline of the surface under process of correction. These 

 iron r'ates, I would say, are simply used for preliminary 

 formation of polishers. I may have something to say on 

 the question of surface plates in the future, as I have made 

 some interesting studies on the subject. I must now 

 bring this paper to a close, although I had intended in- 

 cluding some interesting studies of curved surfaces. There 

 is, however, matter enough in that subject of itself, espe- 

 cially when we connect it with the idiosyncrasies of the 

 material we have to deal with, a vital part of the subject 

 that I have not touched upon in the present paper. You 

 may now inquire how critical is this " colour test." To 

 answer this I fear I shall trench upon forbidden grounds, 

 but I call to my help the words of one of our best American 

 physicists, and I quote from a letter in which he says, " by 

 combined calculation and experiment I have found the 

 limiting error for white light to be ^o o oVoo o °^ ^^ i^^ch, and 

 for Na (or sodium) light about fifty times greater or less than 

 eoo'ooo of ^^ inch." Dr. Alfred Mayer estimated and 

 demonstrated by actual experiment that the smallest black 

 spot on a white ground \-isible to the naked eye is about 

 g^i-j of an inch at the distance of normal vision, namely 

 10 inches, and that a line, which, of course, has the 

 element of extension ^o^ of an inch in thickness could 

 be seen. In our delicate "colour test" we may decrease 

 the diameter of our black spot a thousand times, and still 

 its perception is possible by the aid of our monochromatic 

 light, and we may diminish our line ten thousand times, 

 yet find it just perceivable on the borderland of our test 

 by white light. Do not presume I am so foolish as to even 

 think that the human hand directed by the human brain 

 can ever work the material at his command to such a high 

 standard of exactness. No ; from the very nature of the 

 material we have to work with, we are forbidden even to 

 hope for such an achievement, and could it be possible that, 

 through some stroke of good fortune, we could attain this 

 high ideal, it would be but for a moment, as from the very 

 nature of our environment, it would be but an ignus 

 faiuui. There is, however, to the earnest mind a delight 

 in having a high model of excellence, for as our model is 

 so will our work approximate, and although we may go on 

 approximating our ideal for ever we can never hope to 

 reach that which has been set for us by the great Master 

 Workman. 



THOUGHT AND LANGUAGE. 



By Ada S. Ballin. 



VIII. 



WE have seen how the primitive language of sensation 

 gradually developed into that of emotion, and how 

 from the basis thus formed the language of the will arose. 

 In my last article we were left in that no man's land which 

 lies between actions expressive of will and those which 

 serve to communicate thought ; for it is impossible to fix a 

 definite line between the various phases of mind and their 

 manifestations. Equally difficult is it to define those 



gestures which man and no other animal is capable of per- 

 forming, as there are endless examples recorded of gestures 

 of a very complicated character that could only be the result 

 of complex intellectual acts having been performed by the 

 lower animals. 



The following very striking and mutually corroborative 

 instances will, 1 think, illustrate this point. Captain John- 

 son saw a number of monkeys (Jfaranis rliesiis) on some 

 trees, and he says : — " 1 fired with small shot at one of 

 them, which instantly r.in down to the lowest branch of the 

 tree, as if he were going to fly at me, stopped suddenly, 

 and coolly put his i)aw to the part wounded, covered with 

 blood, and held it out for me to see."* The action said as 

 plainly as possible, " See what a dreadful injury you have 

 done me," and Captain Johnson was so impressed by the 

 mute reproach that he has never since fired at any of the 

 tribe. 



The second case is given by Jesse, and refers to Sir W. 

 Hoste's Memoirs : — " One of his officers, come home after a 

 long day's shooting, saw a female monkey running along 

 the rocks with her young one in her arms. He imme- 

 diately fired, and the animal fell. On his coming up, she 

 grasped her little one close to her breast, and with the 

 other hand pointed to the wound which the ball had made, 

 and which had entered above her breast. Dipping her 

 finger in the blood, and then holding it up, she seemed to 

 reproach him with being the cause of her death, and con- 

 sequently that of the little one, to which she frequently 

 j)ointed. ' I never,' says Sir William, ' felt so much as 

 when I heard the story, and I determined never to shoot 

 one of these animals as long as I lived.' "f 



A similar story is told of the celebrated elephant Chuny. 

 When he was brought to England in 1810 he was engaged 

 to perform at Covent Garden Theatre. It was arranged 

 that in the course of the performance he should pas.s over a 

 bridge. The bridge was not very strongly built, and the 

 animal, feeling it unequal to his weight, resolutely refused 

 to cross it. Blow after blow from an iron goad rained 

 upon the fleshy part of his neck at the root of the ear, until 

 quite a pool of blood was made on the floor. At last Capt. 

 Kay, who had brought Chuny over on his ship, the Ashel, 

 and had petted him a great deal, came to know what was 

 the matter. Before any explanation could be given, Chuny 

 walked up to him, caught his friend's hand in his trunk, 

 thrust it into the bleeding wound, and then held it up 

 before his eyes, thus attracting his attention to the cruelty 

 which had been practised. 



The reasoning in this case is precisely what is called 

 human reasoning, and the comprehension of the relation of 

 cause and efl'ect is very strongly marked ; the gestures de- 

 scribed are also exactly what would be performed by a deaf- 

 and-dumb person under the same circumstances. 

 ■ Another instance, less tragic, but proving even more 

 conclusively the power of reasoning and communication, 

 was received by Mr. Romanes from Lieut. -General Sir John 

 H. Lefroy, C.B., K.C.M.G., F.R.S., who has a terrier 

 which it is the duty of his wife's maid to wash and feed. 

 " It was her habit, after calling her mistress in the 

 morning, to go out and milk a goat which was tethered near 

 the house, and give "Button" the milk. One morning, 

 being rather earlier than usual, instead of going out at 

 once, she took up some needlework, and began to occupy 

 herself. The dog endeavoured in every possible way to 

 attract her attention and draw her forth, and at last 

 pushed aside the curtain of a closet, and, never having been 

 taught to fetch or carry, took between his teeth the cup she 

 habitually used, and brought it to her feet." 



* " Animal Intelligence," p. 475. 

 t " GleaningB," Vol. III., pp. 86-7. 



