On this page
- Departments (1)
- Pictures (1)
-
Text (5)
-
904 THE LEADER. [Saturday,
-
Eittrfititrt.
-
Critics are not the legislators, but the...
-
The great topic of the week is, of cours...
-
The principle of " publishing societies,...
Note: This text has been automatically extracted via Optical Character Recognition (OCR) software. The text has not been manually corrected and should not be relied on to be an accurate representation of the item.
-
-
Transcript
-
Note: This text has been automatically extracted via Optical Character Recognition (OCR) software. The text has not been manually corrected and should not be relied on to be an accurate representation of the item.
Additionally, when viewing full transcripts, extracted text may not be in the same order as the original document.
Pc01605
904 The Leader. [Saturday,
904 THE LEADER . [ Saturday ,
Eittrfititrt.
Eittrfititrt .
Critics Are Not The Legislators, But The...
Critics are not the legislators , but the judges and police of literature . They do not makelawa—they interpret and try to enforcethem . — Edinburgh fieview .
The Great Topic Of The Week Is, Of Cours...
The great topic of the week is , of course , the meeting of the , British Association at Hull . Although we cannot by any means share the official enthusiasm and official hopes respecting the advancement of Science by such means—believing Science takes quite other means—although , moreover , we cannot , like Professor Phillips , regard the expenditure of forty thousand pounds in the course of three and twenty years as a very magnificent indication of the activity and liberality of England ( we should like a comparison to be made with some other item of corporate
expendituresay aldermanic feasts during three and twenty years !)—although we look upon these Meetings very much in the light of huge gatherings for gossip , laudation , and twaddle , relieved from contempt by some serious and useful work—nevertheless , there is one aspect in which we regard them as potent influences : if they do not greatly advance Science , they do greatly advance the popularity of scientific pursuits , and so insensibly prepare the way for the final universal acceptance of Science as the basis of all education . Howlittle do the worthy clergymen and worthy churchmen dream they are fostering their most formidable rival , in thus " patronizing" Science !
The President ' s address was very able . He began by remarking how much more populous our solar system is than was suspected till quite recently . During the last twelve months , nine new planets have been discovered , four by our countryman , Mr . Hind . In fact , the search for them has assumed a systematic shape , and we may hope for a large accession to our astral maps . In noticing the two new theories of Heat , the President ' s Address is so worded as to give greater novelty to them than is actually the case ; but as they will probably be novel to the majority of our readers , we will quote the passage : —
"A theory which proposes to explain the thermal agency by which motive power is produced , and to determine the numerical relations between the quantity of heat and the quantity of mechanical effect produced by it , may be termed a dynamical theory of heat . Caniot was the first to give to such a theory ji mathematical form . . _ I / is theory rested 611 two propositions which were regarded as axiomatic . The first embodied the abstract conception of a perfect thermo-dynamic engine , and has been equally adopted by the advocates of the new theory of heat . Again , suppose a given quantity of heat to enter a body by any process , and thereby to change its temperature and-general physical state ; and then , by a second process , suppose the body to be restored exactly to its primitive temperature and condition , —Carnot ' s second fundamental proposition asserts that the quantity of heat
which passes out of the body into surrounding space , or into other bodies , in the form of heat , during the second operation , is precisely the same as that which passed into the body during the first operation . This view does no t recognise the possibility of heat being lost by conversion into something else—and in this particular it is at variance with the new theory , which asserts that heat may be lost by conversion into mechanical effect . To elucidate this distinction , suppose a quautity of water to be poured into an empty vessel . It might then be asserted that , in emptying the vessel again , wo must pour out just as much water as we had previously poured in . This would be equivalent to Carnot ' s proposition with respect to heat . But suppose a part of tho water whilo in the vessel to be converted into vapour ; then it would not be true that in emptying tho vessel the same quantity
of water , in the form of water , must pass out of the vessel as had before passed into it , since a portion would havo passed out in the form of vapour . This is analogous to the assertion of tho new theory with regard to heat , —which may bo lost , ° according to that theory , by conversion into mechanical effect , in a manner analogous to that in which water may be said to be lost by conversion into vapour . ImlTthe new theory not only asserts generally tho convertibility of heat into mechanical effect , and the converse , —but also more definitely , that , whatever bo the mode of converting the one into the other—and whether boat be employed to produce mechanical effect , or mechanical force be employed to produce heat , —the same quantity of tho 0110 is always the equivalent of the same quantity of tho other This proposition can only bo established by experiment . Rumford , who was 0110 * of tho
first to adopt tho fundamental notion of this theory as regards tho nature of heit mado a rough attempt to determine the relation between the force producing friction and tho heat generated by it ; but it was reserved for Mr . Joulo to lay tho true foundation of this theory by a aeries of experiments which , in the nhilo . sophical discernment with which they were conceived and tho ingenuity with * which they were executed , have not often , perhaps l > eon surpassed . In whatever way ho employed mechanical force to produce heat , he found , approximately , the sune mnn tity of heat produced by the , name , amount of force . U 1 ( . j or ,. j , " ,, ; ,, ost ' inm ( l . ( 1 ' ;„ foot-pounds according to the uaual " mode in practical mechanic * " - / ; ,- by tho motive power employed in raising a weight of 1 Hi . through the space of one foot Tho conclusion adopted by Mr . , Ionic is , tlnii ; J" Kahr . in equivalent , to 772 footpounds" ^ '
It may be 1 added , that Professor Thomson and Mr . Jovuk are em-wed in an extensive series of experiments on this subject . h < * " * The President ' s expression of opinion respecting the vcxata qua : st . io of Geology is of , great value , ' from his deservedly high , position in that
:- — " Some of tho most interesting of recent discoveries in organic , remains arc those which prove tho ' existence of reptilian lifo during the deposition of m \\\ o of our oldest foHniliforous strata . An almost perfect skeleton of a reptile beloiifin ^ ( o |] , Ufttrnchiaas or Lnoertians was lately found in the Old Rod . Sandstone " oMVIontv shiro . Tho re-mains of 11 reptile were also discovered last year hy Sir Clni ' ies Lycll and Mr . DawKon in tho coal measures of Nova . Scotia ; um ' l a hat . nw ' hnid fossil ban also boon rccogriiuori in British coal shale . Hut tho most curious evidence of the early existence of aniinnlH above tho lower orders of organization on the fae <> ot our globe , ia that afforded by tho footprint * discovered " u short tiino a-o iu
Canada by Mr . Logan , on large slabs of the oldest fossiliferous rocks , — -those of th Silurian epoch . It was inferred from the more imperfect specimens first broi hf over , that these footmarks were the marks of some reptile ; but more nef f examples , afterwards supplied by Mr . Logan , satisfied Prof . Owen that they w the impressions of some animal belonging to the Articulata , probably a crusta ^ Thus the existence of animals-of the reptile type of organization during ^ tT ' carboniferous and Devonian periods is clearly established j but no evidence has vT been obtained of the existence of those animals during the Silurian period - Aft the "discoveries which I have mentioned , however , few geologists will perhaps iT surprised should we hereafter find that higher forms of animal life were introd < 1 upon the earth during this early period than have yet been detected in its sedi mentary beds .
" Many of you will be aware that there are two theories in geology ; . which m be styled the theories of progression and of non-progression respectively Th former asserts that the matter which constitutes the earth has passed throuo-1 continuous and progressive changes from the earliest state in which it existed ! its actual condition at the present time . The earliest state here contemplated mav have been a fluid , or even a gaseous state , due to the enormous primitive heat of the mass , and it is to the gradual loss of that heat that the progressive chance recognised by this theory is chiefly attributed . The theory of non-progressio n on the contrary , recognises 110 primitive state of our planet differing essentially-from
its existing state . The only changes which it does recognise being those which are strictly periodical , and therefore produce no permanent alteration in the state of our globe . With reference to organic remains , the difference between these theories is exactly analogous to that now stated with reference to inorganic matter The theory of progression asserts that there has been a general advance in the forms of organic life from the earliest to the more recent geological periods . This advance must not be confounded , it should be observed , with that progressive development according to which animals of a higher organic structure are but tlip
improved lineal descendants of those of the lowest grade , thus abolishing all distinction of species . It is merely meant to assert that the higher types of organic being are far more generally diffused at the present time , and far more numerous and varied than they were at the earlier geological periods ; and that , mor eover at the earliest of those periods which the geologist has been able to recognise , some of these higher types had probably no existence at all . " Each successive discovery , like those which I have mentioned , of the remains of animals of the higher types in the older rocks , is regarded by some geologists as an addition to the cumulative evidence by which they conceive that the theorv of
non-progression will be ultimately established ; while others consider the deficiency in the evidence required to establish that theory as far too great , to admit the probability of its being supplied by future discovery . Kbr can the theory derive present support , it is contended , by an appeal to any properties of inorganic matter , or ^ physical laws , with which we are acquainted . Prof . W . Thomson has recently entered—into some very interesting speculations bearing on this subject , and suggested by the new theory of heat of which I have spoken . The heat of a heavenly body placed under the same conditions as the sun , must , it has been said , be ultimately exhausted by its rapid emission . This assertion assumes the matter composing the sun to have certain properties like those of terrestrial matter with respect to the generation and emission of heat ; but Prof . Thomson ' s argument
places the subject on better grounds , admitting , always , tho truth of the new theory of heat . That theory asserts , in the sense which I have already stated , the exact equivalence of heat and motive power ; and that a body , in sending forth heat , must lose a portion of that internal motion of its constituent particles on which its thermal state depends . Now , wo know that no mutual action of these constituent particles can continue to generate motion which might compensate for tho loss of motion thus sustained . This is a simple deduction from dynamical laws and principles , independent of any property of terrestrial matter which may possibly distinguish it from that of the sun . Hence , then , it is on these dynamical principles that we may rest the assertion that tho sun cannot continue for an
indefinite time to emit the same quantity of heat as at present , unless his thermal energy be renovated from some extraneous sourco . The same conclusion may he applied to all other bodies in the universe which , like our sun , may be centres of intense boat ; and , hence , recognising no adequate external supplies of heat to renovate these existing centres of heat , Prof . Thomson concludes that the dispersion of heat , and consequently of physical energy , from the sun and stars into surrounding : space without any recognisable means of re-concentration , is tho existing order of Nature . Jn . such case , the boat of the sun must ultimately bo diminished , and the physical condition of the earth therefore altered , in 11 degree altogether inconsistent with the theory of non-progression .
" If wo are to found our theories upon our knowledge , and not upon our ignorance of physical causes and phenomena , I can only recognise in tho existing staff of things a passing phaso of tho material universe . It , may be calculated in all , and ia deinonstrably so xin some respects , to endure under the action of known causes , for an inconceivable period of time ; but it has not , I think , received tlio impress of eternal duration in characters which man is able to decipher . Tho external temperature any physical conditions of our own globe may not , and probably cannot , have changed in any considerable dem-co wince tho first introduction oi Htnto
organic beings on its surface ; but J can still only recogni . se in its physical ( hiring all geological periods , a state of actual though of exceedingly slow prog" * - won , from an antecedent to . some ultimate utatc , on the nature of which our limited powers will not , enable uh to oiler any conjecture founded on physical research . ''''l <) theories , even , of which I have been speaking , may probably appear to some pernon * as not devoid of presumption ; but for inuny men they will over bo fraught wit " ( loop speculative interest : and , let me add , no charge of presumption can justly lm against them if entered upon with that caution and modesty which ought to gi » ( l <) our inquiries in these remote regions of physical science /'
We notice with extreme regret that applications , made both to -Lord . Drkiiy and Lord Aiikkdekn , for a grant to aid in the publication of Mr . IFuxi . ky'h Zoological and Physiological Researches in II . M . S . RattlesiU'kv have been inuHcctual . What" votes" can Zoology and Ph ysiology « 'v 0 that they should have money spent on them ? What linn Protection or Coalition to < lo with the advance ! of Science ?
The Principle Of " Publishing Societies,...
The principle of " publishing societies , " which enables sections oft '' public to secure ; works , by co-operation , such as no publisher would "n "" rJ tuke , lmw been found eminentl y successful in the eases yet tried , * . <* '•* tll °
-
-
Citation
-
Leader (1850-1860), Sept. 17, 1853, page 16, in the Nineteenth-Century Serials Edition (2008; 2018) ncse.ac.uk/periodicals/l/issues/cld_17091853/page/16/
-