310 MR. J. C. DYER ON 



importance that we should have some faithful records of 

 the successive steps taken among our most talented ma- 

 chinists to bring into their present state those gigantic 

 aids to manufacturing industry which at once contribute 

 so largely to our national wealth and power and afford 

 so fair a ground of patriotic pride. This task can only be 

 well performed by some of those who have witnessed or 

 contributed to the gradual approaches to such triumphant 

 issues of the labour, skill, and talent so long and patiently 

 employed in working out these results*. A concise ac- 

 count should be given of the manipulations of the cotton 

 before it comes to the roving-frame : — (1) By the " devil- 

 ling-machine/^ for opening the cotton from its compressed 

 state in the bags. (2) Blowing-engine, for clearing and 

 separating it from dirt and extraneous bodies. (3) The 

 carding-engines for arranging the fibres in even sheets, 



* If we wish to know how any work is performed, we must consult those 

 who have done the same kind of work. If we desire to understand the 

 properties of any machine, we should hare them explained by persons con- 

 versant with the construction of such machines. 



In like manner, if we can hope to see plain and reliable accounts given of 

 the progressive advances made in labour-saving machinery of late years, 

 they must come (as said in the text) from " some of those who have witnessed 

 and contributed to the gradual approaches to the state of perfection " now 

 attained. I would therefore invoke the pens of the few eminent men still 

 left who belong to the class thus named, to record (as I have humbly sought 

 to do) their own knowledge and experiences respecting the many other able 

 contributors to the rapid advances in the science of practical mechanics in 

 our times. 



I may here point to the example set by my highly gifted friend, William 

 Pairbairn, LL.D. &c., whose long course of engineering practice and 

 scientific labours have been of the highest order and importance in widening 

 the fields and clearing the paths of the mechai^cal engineer ; for Mr. 

 Fairbairn has given to the public, through his valuable lectures and published 

 works, the results of his experiments, and the principles disclosed by them, 

 as well as of his engineering labours, all of which are so plainly set forth as 

 to enable the working man to comprehend them. 



I greatly wish that another much valued and able friend, Mr. Henry 

 Houldsworth, would perform the same task respecting his own important 

 inventions and labours for advancing the mechanical sciences, second only 

 to those of Fairbairn. 



