MR. J. C. DYER ON COTTON-SPINNING MACHINERY. 297 



ferrous oxides and sodie sulphates, when exposed to sun- 

 light becomes yellow j and possibly some of these balls may 

 have changed in colour since they came from the flue. 

 Hydrochloric and nitric acids exert very little action on the 

 ferruginous globes : this may be due, in some measure, to 

 the high temperature at which the oxides have been formed ; 

 in other cases they are no doubt protected by an external 

 coating of some silicate. It would require much time 

 and patience to collect a sufficient number of each kind 

 of these minute objects for a chemical analysis ; but the 

 spectroscope might probably assist in revealing their con- 

 stitution. When time permits, I hope to resume the 

 subject. 



XXVII. Notes on Cotton-Spinning Machinery. Roving - 

 Frames. By J. C. Dyer, V.P. 



Read March 20th, 1866. 



In the preparation of cotton for spinning, several distinct 

 classes of machines are employed, such as the clearing, 

 scutching, and blowing machines, and the carding, dou- 

 bling, and drawing engines, by which cotton is brought into 

 the state of continuous slivers, or " rovings,^^ before it 

 comes to the "roving-frames.^^ These operations for 

 clearing, carding, and arranging the fibres into loose 

 ropes oi" rovings, are of a simple nature, and are sufficiently 

 indicated by the names of the several machines used for 

 that purpose ; and as no special description of them seems 

 called for, I proceed to consider the more intricate and 

 scientific properties of the machines known as roving- 

 frames, which come next to the mule-jenny in the order 

 of scientific interest, on the ground of their having also 



SER. III. VOL. III. X 



