126 Mr. J. Taylor on the Accidents 



nuper vidi sub hoc nomine inter alias rarissimas plantas 

 in horto Dom. Tate, in vico Sloane-street. 



Habitus forte ut in C. triquctro Nob. — Flores ignoti : 

 sed prope id locarem. St. ^ . 



gracilis. C. (slender, long-spined) suberectus, teretiusculus : 

 10. spinis antiquis solitariis rectis uncialibus, incipientibus 

 geniinatis plusve, albis. 



Habitat in America calidiore. St. ^ . 



Obs. Unam plantam 4-entalem virescentem simpli- 

 cem apud Dom. Loddiges solum vidi, cum duabus 

 incipientibus ramulis recenter pullulatis. Plantse facies 

 est fere ut in Euphorbia Hystrix Auctorum, at adhue 

 minus spinosa, duplo brevioribus spinis. An rami in 

 aelate 3-angulares ? Flores adhuc ignoti. Aflfinis 

 fortasse Cerei 7iani Kunz : (quod non vidi) et prope 

 id locarem ; sed nihilominus forte longe major, et sine 

 areolis; ut in Cereo nano. 

 P.S. Having, since my last communication, detected an 

 error in my fourth Decade of New Succulent Plants, page 33, 

 line 13, (in the Philosophical Magazine for August 1823), 

 have the goodness to notice it as follows : 



" For hasmisphericae, read orbiculari." 



XXIX. On the Accidents incident to Steam Boilers*. By 



John Taylor, Esq. F.R.S. F.G.S. F.H.S. 

 TT has been remarked by some practical men who have had 

 -■■ most opportunity of examining the circumstances under 

 which the bursting of boilers has taken place, that the causes 

 have sometimes appeared to be not of that simple character 

 which is commonly assigned to them ; and that some such ac- 

 cidents have occurred where neither excessive expansive force 

 of steam, neglect of the usual precaution, weakness of material 

 or bad construction, existed to a degree equal to the effect. 

 Mr.Woolf in a conversation upon this subject some time since, 

 expressed to me his opinion of some case where, as he thought, 

 there was ground to suspect the operation of an explosion of 

 gas in the flues, or at least outside the boiler. Any inquiry 

 or discussion into the causes of circumstances which continue 

 to be a reproach to our mode of using steam, must, I conceive, 

 be useful ; and my principal object will rather be to provoke 

 it, and to encourage a record of tacts, than to propound any 

 particular theory of my own, though I admit that some re- 

 cent cases appear to countenance Mr. Woolf's idea. 



In the mines of Cornwall, and in those of North Wales, the 

 * ComiminiciUcd bv tlie Author. 



