Mechanical Science. 139 



intended for a matrix ; it is then placed under a strong press, 

 which forces down the letters into the lead, which thus becomes 

 a solid matrix. In this matrix as many stereotype forms may 

 be cast as can be wanted. The composition for casting the 

 moveable characters is formed of seven parts by weight of lead, 

 two of regulus of antimony, and one of an alloy of tin and cop- 

 per, in the proportion of nine of tin, to one of copper. — Neio 

 Monthly Magazine, ix. 71. 



The alloy with which to oast the p/a^es should also have been 

 described. — Ed. 



7. Calculating Engine. — At page 222, of our 14th volume, 

 we have inserted a notice of Mr. Babbage's very curious 

 investigations on the application of machinery to the purpose 

 of calculating and printing mathematical tables. It gives us 

 much pleasure to be able to inform our readers, that he is dili- 

 gently pursuing this very important subject, and that the re- 

 sults of his labours are in the highest degree satisfactory. 



8. English Opium. — Messrs. Cowley and Staines, of Winslow, 

 Bucks, have cultivated poppies for opium with such success, as 

 to induce the belief that that branch of agriculture is of national 

 importance, and worthy of support. In the year 1821, they pro- 

 duced 60 lbs. of solid opium, equal to the best Turkey opium, 

 from rather less than four acres and a half of ground. The 

 seed was sown in February, came up in March, and, after pro- 

 per hoeing, setting out, &c., the opium gathering commenced 

 at the latter end of July. The criterion for gathering the opium 

 was, when the poppies, having lost their petals, were covered with 

 a bluish-white bloom. The scarificator, an instrument contain- 

 ing five small blades, was then applied to them, horizontal inci- 

 sions being preferred, because the juice was not so apt to run 

 from them before inspissation. After being scarified in one 

 aspect, the head was left until the juice was coagulated (about 

 two hours,) it was then removed by gatherers, and fresh inci- 

 sions made on other parts. The poppies were found to produce 

 opium freely, until the third or fourth incision, and some of 

 them even to the tenth. Opium was gathered daily until, at 

 the rate of 30s. per lb., the produce would no longer bear the 

 expense; 97 lb. 1 oz. were procured at an expense of 

 3U. lis. 2M., and this, when evaporated sufficiently in the 

 bun, produced above GO lb. of properly dried opium. 



