190 Mr. Samuel Seaward on High-pressure Gauges. 



From the analysis above detailed, it is evident that the mi- 

 neral from the Kaiserstuhl is actually a new one. The name 

 hyalosiderite has been suggested by its properties and its com- 

 position, and is derived from vu\o§ glass, and <n8>]goj iron. 

 The formation of this mineral, it is probable, could not have 

 been the result of operations like those by which the primitive 

 rocks were produced ; and we may thence assume, that the 

 rock in which it occurs is of volcanic origin. 



XXXIII. On High-pressure Gauges. By Mr. Samuel 

 Seaward. 



To the Editors of the Philosophical Magazine and Journal. 

 Gentlemen, 



IT is highly creditable to the taste of your ingenious cor- 

 respondent Mr. H. Russell, that he can extract so much 

 amusement from the manufacturing of high-pressure gauges. 

 I hope no one will be so selfish as to envy him the recreation 

 of this harmless pursuit, more especially as he appears very 

 prudently to confine his views to his own individual grati- 

 fication. 



Complexity in a machine or instrument should certainly 

 be as much as possible avoided ; but if all instruments are to 

 be condemned which have a diversity of parts (which I un- 

 derstand by the term complex), we should never have en- 

 joyed the benefits of a clock, a loom, or a steam-engine. 



My idea of a high-pressure gauge is, that it should be use- 

 ful ; but if it is intended to be merely an amusing toy, why 

 then I should commend Mr. Russell's choice of what he lauds 

 so much as being simple and easy. 



The instrument described by your correspondent in the 

 last Number of your Magazine, is substantially the same as 

 the common gauge which has been in use a long time past at 

 the Portable Gas Works, where its defective and uncertain 

 operation has been long known, — practically known in the 

 way of business, not speculatively conjectured : in confirma- 

 tion of which I beg to state, that the superintendants of that 

 establishment were lately in serious contemplation of erecting 

 a <rauo-e 70 feet long, in order that the divisions of the scale 

 might be of adequate length. This simple fact is, I think, a 

 complete answer to Mr. Russell's crudities. 



Mr. R. seems to entertain great fear of its being practicable 

 to make a " tight joint between the glass tube and metal box." 



