172 Second Essay, preliminary/ lo the Series (>/' Reports 



deck for the taking of' a lunar, while the conclusion of the cal- 

 culation brought the vessel within sight of Cape Clear. 



There is more necessary, however, than the nightly toil of the 

 astronomer. Hadley must contrive his quadrant, and Trough- 

 ton must improve it — Newton must detect the chromatic obser- 

 vation of light, and DoUond correct it ; Huygens must investi- 

 gate the phenomena of vibration and contrive the chronometer; 

 and the endless series of improvements must be made on that 

 instrument ere the ship can boldly leave the land astern, and 

 trust herself to the interminable ocean. 



I have now rudely analyzed the process of transportation, and 

 have traced the cotton wool to its native shore. But much yet 

 has to be done ere I have completed the first part of my inves- 

 tigation. The toil of the cotton planter, the instruments which 

 he employs, and a long train of improvements, have all to be 

 considered. We must examine the machinery which clears the 

 cotton of its seeds, and must return to our own country to view 

 the slow lathe cutting out the ponderous cylinder. Ignorance 

 of the subject, however, compels me to leave that part untouch- 

 ed, and I shall now proceed to analyze, in the same hasty man- 

 ner, the process of converting the raw cotton wool into the cable 

 twist. 



The detail of the various movements, — the description of the 

 multitudes of ingenious contrivances, — the history of their in- 

 troduction, would swell this merely speculative essay into a for- 

 midable quarto ; and I must content myself with a glance at the 

 general aspect of the machinery. 



The toothed wheel, the steel arbour, and the all-uniting 

 screw, are the more prominent parts ; and the formation of these 

 essentials offers thus the most important features in the manu- 

 facture of machinery. Wh^n we walk through the various 

 works we observe one mandril used in the formation of another ; 

 one divided plate producing thousands of others; one planing 

 engine occupied in the construction of slide rests, which are on- 

 ly planing engines in another form ; and one screw reproducing 

 new screws of every variety of pitch and thread. And when we 

 inquire whence came these parent plates, lathes, planing cn- 

 o-ines, and screws, we are answered that these were themselves 

 deduced from others of acknowledged excellence. A first glance 



