May io. 1900] 



NATURE 



29 



the example of Nymp/iaca, in which the presence of 

 centrosomes has recently been insisted on, Strasburger 

 shows that not only can the occasional granules not be 

 identified as centrosomes, but that the spindle often reaches 

 to and ends on the peripheral layer of the cytoplasm in 

 a multipolar fashion. 



Naturally the bodies known as blepharoplasts are also 

 brought under discussion. These structures have by 

 some been identified with centrosomes, but they seem 

 really to be but remotely related to them. The fact that, 

 as was shown by Webber, the true spindle often becomes 

 multipolar, notwithstanding the presence of blepharo- 

 plasts, tells strongly against their centrosomic character, 

 whilst the fact that in the earliest stages radiations start 

 from them proves absolutely nothing at all. Fischer 

 has shown how heterogeneous bodies may serve as 

 starting-points for radiations in fixed specimens of al- 

 bumin ; and Guignard has described and figured, in the 

 case of the lily, similar radiations having the entire 

 nucleus as their common centre. Much more definite is 

 the relationship existing between the blepharoplasts and 

 cilia. Strasburger, who regards them as essentially con- 

 sisting of kinoplasm, adduces a series of observations in 

 support of the view that they, or bodies like them, are 

 constantly associated with cilia. Certainly it is a fact 

 of no small significance that whilst, in ferns and cycads, 

 they should be absent from all the other nuclear divi- 

 sions, they are constantly present in those which directly 

 lead to the formation of the motile antherozoids. More- 

 over, R. Hertwig has found an analogous relation to hold 

 good for Actinospherium, stating that "centrosomes" 

 only occur in connection with the polar {Richtungs) 

 mitoses, whilst they are quite absent from the somatic 

 divisions. 



It is not possible to touch, even briefly, on all the 

 points raised and illustrated in Prof. Strasburger's book ; 

 it is hoped, however, that enough has been said to in- 

 dicate its importance as embodying, not only a consider- 

 able number of new facts, but also many new and sug- 

 gestive points of view. 



And throughout the volume one is struck, not only by 

 the full recognition accorded to the work of other in- 

 vestigators in the same field, but by the invariable 

 courtesy which characterises the author's criticism of 

 their results even when these do not accord with those 

 obtained by himself. J. B. Farmer. 



MODERN POWER LOOMS. 



Mechanism of Weaving. By T. W. Fox. Pp. xxii +514. 



(London : Macmillan and Co., Ltd., 1900.) 

 HTHE second edition of this excellent book, on the con- 



^ struction and working of the power loom, has been 

 carefully revised by the author. It has justly been 

 recognised as a standard text-book on the subject of 

 loom mechanism The work treats of tappet, dobbie, 

 and Jacquard or harness looms. In the first place, a full 

 exposition is given of the tappet shedding motion, refer- 

 ence being made to the Yorkshire tappet loom, Wood- 

 croft and segment tappets, and also to the dififerent 

 under motions for the depression of the heald shafts. 

 Proceeding, Mr. Fox deals with some of the principal 

 types of dobbies, such as the Blackburn, Keighley, Burn- 

 >-o 1 593. VOL. 62] 



ley and American. By means of sectional drawings, the 

 somewhat intricate mechanism of these dobbies is clearly 

 described. The work would have been enhanced to the 

 manufacturer of heavy fabrics, such as linen, woollen and 

 worsted textures, if fuller descriptions had been given 

 of the dobbies employed in the weaving of these fabrics. 

 Still, to the student of cotton weaving and the manufac- 

 turer of light fabrics, the information supplied will be found 

 invaluable, and even the makers of heavier cloths might 

 consult the pages on dobbies with profit. It is open to 

 dispute whether the best method of treatment has been 

 adopted, from a student's standpoint, in dealing fully 

 with shedding motions, including the Jacquard, and card 

 stamping, and the methods of tieing up the harness, 

 before reference is made to other essential motions of the 

 loom ; but the plan of the author is evident on only a 

 casual examination of the book, namely, to treat of each 

 distinct motion in all its various forms in succession, 

 excluding the possibility of affording the reader at the 

 outset even a general notion of the combination of 

 movements in power-loom weaving. This explains why 

 some 280 pages, or more than half the book, should be 

 devoted to the principles of shedding, card stamping 

 and harness mounting, prior to any descriptive reference 

 being made to the picking, the warp let-ofiF, fabric take- 

 up, shuttle, and other motions. 



In dealing with the Jacquard loom, the single-lift 

 machine — the basis on which all Jacquards are con- 

 structed — is first treated of ; then follow descriptions of the 

 double-lift, centre-shed, open-shed, twilling, Bessbrooke 

 and cross-border machines. The doup and gauze harness 

 are very clearly explained. Other systems of tie-up, 

 more elaborately illustrated, might have been advan- 

 tageously incorporated into this section of the work ; but 

 sufficient data is afforded to enable the student to grasp 

 the principles on which the complex mountings are 

 effected, necessary in the weaving of tapestry and 

 decorative silk fabrics. 



Lappet weaving receives adequate attention, especially 

 as worked by means of lappet wheels and the Scotch 

 method ; but only brief details are given on other forms 

 of this motion, in which lags are used and pegs of 

 different lengths, and also in which the frames for carry- 

 ing the lappet threads operate on the upper side of the 

 fabric. 



In regard to picking, Mr. Fox gives some interesting 

 information on the magnitude of the force expended in 

 propelling the shuttle from side to side of the loom. 

 Perhaps there is no motion in weaving in which improve- 

 ment is so desirable as in picking. This is more obvious 

 in heavy looms, where large shuttles have to be used, 

 travelling at a high speed. Under the head of " Warp 

 Protectors," fast and loose reeds are considered, as well 

 as shuttle guards. Many attempts have been made at 

 automatic warp-stop motions, such as those applied to 

 the Northrop and Poyser looms, but probably the author 

 has not mentioned these on account of their not having 

 come into general use in this country ; still, there are 

 principles in both interesting to the student of 

 " Mechanism of Weaving." 



The chapter on " Multiple Box Motions " is one very 

 typical of the author's skill in the exposition of difficult 

 mechanical problems. Revolving, as well as drop-box 



