a history of science-1-第7章

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　in　part　under　Asiatic　influences；　and　that　unique　style　of　stilted　yet　expressive　drawing　had　come　into　vogue；　which　was　to　be　remembered　in　after　times　as　typically　Egyptian。　More　important　than　all　else；　our　Egyptian　of　the　earliest　historical　period　was　in　possession　of　the　art　of　writing。　He　had　begun　to　make　those　specific　records　which　were　impossible　to　the　man　of　the　Stone　Age；　and　thus　he　had　entered　fully　upon　the　way　of　historical　progress　which；　as　already　pointed　out；　has　its　very　foundation　in　written　records。　From　now　on　the　deeds　of　individual　kings　could　find　specific　record。　It　began　to　be　possible　to　fix　the　chronology　of　remote　events　with　some　accuracy；　and　with　this　same　fixing　of　chronologies　came　the　advent　of　true　history。　The　period　which　precedes　what　is　usually　spoken　of　as　the　first　dynasty　in　Egypt　is　one　into　which　the　present…day　searcher　is　still　able　to　see　but　darkly。　The　evidence　seems　to　suggest　than　an　invasion　of　relatively　cultured　people　from　the　East　overthrew；　and　in　time　supplanted；　the　Neolithic　civilization　of　the　Nile　Valley。　It　is　impossible　to　date　this　invasion　accurately；　but　it　cannot　well　have　been　later　than　the　year　5000　B。C。；　and　it　may　have　been　a　great　many　centuries　earlier　than　this。　Be　the　exact　dates　what　they　may；　we　find　the　Egyptian　of　the　fifth　millennium　B。C。　in　full　possession　of　a　highly　organized　civilization。　All　subsequent　ages　have　marvelled　at　the　pyramids；　some　of　which　date　from　about　the　year　4000　B。C。；　though　we　may　note　in　passing　that　these　dates　must　not　be　taken　too　literally。　The　chronology　of　ancient　Egypt　cannot　as　yet　be　fixed　with　exact　accuracy；　but　the　disagreements　between　the　various　students　of　the　subject　need　give　us　little　concern。　For　our　present　purpose　it　does　not　in　the　least　matter　whether　the　pyramids　were　built　three　thousand　or　four　thousand　years　before　the　beginning　of　our　era。　It　suffices　that　they　date　back　to　a　period　long　antecedent　to　the　beginnings　of　civilization　in　Western　Europe。　They　prove　that　the　Egyptian　of　that　early　day　had　attained　a　knowledge　of　practical　mechanics　which；　even　from　the　twentieth…century　point　of　view；　is　not　to　be　spoken　of　lightly。　It　has　sometimes　been　suggested　that　these　mighty　pyramids；　built　as　they　are　of　great　blocks　of　stone；　speak　for　an　almost　miraculous　knowledge　on　the　part　of　their　builders；　but　a　saner　view　of　the　conditions　gives　no　warrant　for　this　thought。　Diodoras；　the　Sicilian；　in　his　famous　World's　History；　written　about　the　beginning　of　our　era；　explains　the　building　of　the　pyramids　by　suggesting　that　great　quantities　of　earth　were　piled　against　the　side　of　the　rising　structure　to　form　an　inclined　plane　up　which　the　blocks　of　stone　were　dragged。　He　gives　us　certain　figures；　based；　doubtless；　on　reports　made　to　him　by　Egyptian　priests；　who　in　turn　drew　upon　the　traditions　of　their　country；　perhaps　even　upon　written　records　no　longer　preserved。　He　says　that　one　hundred　and　twenty　thousand　men　were　employed　in　the　construction　of　the　largest　pyramid；　and　that；　notwithstanding　the　size　of　this　host　of　workers；　the　task　occupied　twenty　years。　We　must　not　place　too　much　dependence　upon　such　figures　as　these；　for　the　ancient　historians　are　notoriously　given　to　exaggeration　in　recording　numbers；　yet　we　need　not　doubt　that　the　report　given　by　Diodorus　is　substantially　accurate　in　its　main　outlines　as　to　the　method　through　which　the　pyramids　were　constructed。　A　host　of　men　putting　their　added　weight　and　strength　to　the　task；　with　the　aid　of　ropes；　pulleys；　rollers；　and　levers；　and　utilizing　the　principle　of　the　inclined　plane；　could　undoubtedly　move　and　elevate　and　place　in　position　the　largest　blocks　that　enter　into　the　pyramids　orwhat　seems　even　more　wonderfulthe　most　gigantic　obelisks；　without　the　aid　of　any　other　kind　of　mechanism　or　of　any　more　occult　power。　The　same　hands　could；　as　Diodorus　suggests；　remove　all　trace　of　the　debris　of　construction　and　leave　the　pyramids　and　obelisks　standing　in　weird　isolation；　as　if　sprung　into　being　through　a　miracle。

ASTRONOMICAL　SCIENCE　It　has　been　necessary　to　bear　in　mind　these　phases　of　practical　civilization　because　much　that　we　know　of　the　purely　scientific　attainments　of　the　Egyptians　is　based　upon　modern　observation　of　their　pyramids　and　temples。　It　was　early　observed；　for　example；　that　the　pyramids　are　obviously　oriented　as　regards　the　direction　in　which　they　face；　in　strict　accordance　with　some　astronomical　principle。　Early　in　the　nineteenth　century　the　Frenchman　Biot　made　interesting　studies　in　regard　to　this　subject；　and　a　hundred　years　later；　in　our　own　time；　Sir　Joseph　Norman　Lockyer；　following　up　the　work　of　various　intermediary　observers；　has　given　the　subject　much　attention；　making　it　the　central　theme　of　his　work　on　The　Dawn　of　Astronomy。＇1＇　Lockyer's　researches　make　it　clear　that　in　the　main　the　temples　of　Egypt　were　oriented　with　reference　to　the　point　at　which　the　sun　rises　on　the　day　of　the　summer　solstice。　The　time　of　the　solstice　had　peculiar　interest　for　the　Egyptians；　because　it　corresponded　rather　closely　with　the　time　of　the　rising　of　the　Nile。　The　floods　of　that　river　appear　with　very　great　regularity；　the　on…rushing　tide　reaches　the　region　of　Heliopolis　and　Memphis　almost　precisely　on　the　day　of　the　summer　solstice。　The　time　varies　at　different　stages　of　the　river's　course；　but　as　the　civilization　of　the　early　dynasties　centred　at　Memphis；　observations　made　at　this　place　had　widest　vogue。　Considering　the　all…essential　character　of　the　Nile　floods…without　which　civilization　would　be　impossible　in　Egyptit　is　not　strange　that　the　time　of　their　appearance　should　be　taken　as　marking　the　beginning　of　a　new　year。　The　fact　that　their　coming　coincides　with　the　solstice　makes　such　a　division　of　the　calendar　perfectly　natural。　In　point　of　fact；　from　the　earliest　periods　of　which　records　have　come　down　to　us；　the　new　year　of　the　Egyptians　dates　from　the　summer　solstice。　It　is　certain　that　from　the　earliest　historical　periods　the　Egyptians　were　aware　of　the　approximate　length　of　the　year。　It　would　be　strange　were　it　otherwise；　considering　the　ease　with　which　a　record　of　days　could　be　kept　from　Nile　flood　to　Nile　flood；　or　from　solstice　to　solstice。　But　this；　of　course；　applies　only　to　an　approximate　count。　There　is　some　reason　to　believe　that　in　the　earliest　period　the　Egyptians　made　this　count　only　360　days。　The　fact　that　their　year　was　divided　into　twelve　months　of　thirty　days　each　lends　color　to　this　belief；　but；　in　any　event；　the　mistake　was　discovered　in　due　time　and　a　partial　remedy　was　applied　through　the　interpolation　of　a　〃little　month〃　of　five　days　between　the　end　of　the　twelfth　month　and　the　new　year。　This　nearly　but　not　quite　remedied　the　matter。　What　it　obviously　failed　to　do　was　to　take　account　of　that　additional　quarter　of　a　day　which　really　rounds　out　the　actual　year。　It　would　have　been　a　vastly　convenient　thing　for　humanity　had　it　chanced　that　the　earth　had　so　accommodated　its　rotary　motion　with　its　speed　of　transit　about　the　sun　as　to　make　its　annual　flight　in　precisely　360　days。　Twelve　lunar　months　of　thirty　days　each　would　then　have　coincided　exactly　with　the　solar　year；　and　most　of　the　complexities　of　the　calendar；　which　have　so　puzzled　historical　students；　would　have　been　avoided；　but；　on　the　other　hand；　perhaps　this　very　simplicity　would　have　proved　detrimental　to　astronomical　science　by　preventing　men　from　searching　the　heavens　as　carefully　as　they　have　done。　Be　that　as　it　may；　the　complexity　exists。　The　actual　year　of　three　hundred　and　sixty…five　and　（about）　one…quarter　days　cannot　be　divided　evenly　into　months；　and　some　such　expedient　as　the　intercalation　of　days　here　and　there　is　essential；　else　the　calendar　will　become　absolutely　out　of　harmony　with　the　seasons。　In　the　case　of　the　Egyptians；　the　attempt　at　adjustment　was　made；　as　just　noted；　by　the　introduction　of　the　five　days；　constituting　what　the　Egyptians　themselves　termed　〃the　five　days　over　and　above　the　year。〃　These　so…called　epagomenal　days　were　undoubtedly　introduced　at　a　very　early　period。　Maspero　holds　that　they　were　in　use　before　the　first　Thinite　dynasty；　citing　in　evidence　the　fact　that　the　legend　of　Osiris　explains　these　days　as　ha