﻿208 Prof. A. Lielegg on the Spectra of the 



The flutings a b, bc f &c. (of which there are about ten or twelve) 

 are about 4 inches broad and an inch deep. 



On page 368 it is stated that " an iceberg 100 feet in thick- 

 ness will exert just as much pressure as one a mile in thickness." 

 This cannot be so. An iceberg 100 feet thick when afloat will 

 displace water weighing (suppose) 100 tons, but one a mile 

 thick will displace water weighing (suppose) 10,000 tons. These 

 quantities are equal to the respective weights of the icebergs 

 while afloat. Now let it be supposed that the two icebergs are 

 each propelled by a storm at the rate of three miles an hour, and 

 it must be evident that, when they each come in contact with a 

 rocky bottom, the latter will exert 100 times as much force as 

 the former and produce strise far greater. 



Jersey, January 25, 1869. 



XXVIII. Contributions to the Knowledge of the Spectra of the 

 Flames of Gases containing Carbon. By Andrew Lielegg, 

 Professor at the National Upper Practical School at St. Pol- 

 ten, Austria*. 



T the time when I was making my observations on the 

 spectrum of the Bessemer-flamef, I conceived the idea of 

 investigating what similarity or difference existed between this 

 spectrum (which is, in fact, that of the flame of oxide of carbon) 

 and the spectra of the flames of other gases which contain carbon. 

 It seemed to me that data might also thus be obtained for the 

 solution of the question, whether all spectra of gases containing 

 carbon are really to be regarded as spectra of carbon, or whether 

 every such gas has its own peculiar spectrum. 



With this object in view, I undertook to examine the spectra 

 of light carburetted hydrogen, of olefiant gas, and of cyanogen, 

 and came thus to the knowledge, concerning the two former 

 gases, of some details which, in the greater works already be- 

 fore us on this subject, have either not been noticed at all, or 

 at least have not been described as seen in the manner in which 

 I have had the opportunity of observing them. In communi- 

 cating, then, in the following pages, these details as contribu- 

 tions to our knowledge of the spectra of ignited bodies, I give 

 also the results which I have been able to obtain from a compa- 

 rison of the Bessemer-spectrum with the spectra of other flames. 



* Translated and communicated by W. T. Lynn, B.A., F.R. A.S., of the 

 Royal Observatory, Greenwich, having been read at the Meeting of the 

 Vienna Academy of Sciences on April 16, 1868. 



f See my translations of Professor Lielegg's papers on that subject in 

 the Philosophical Magazine, vol. xxxiv. p. 302. — W. T. L. 



