▁in ▁one ▁time pie ce . ▁It ▁is ▁an ▁astronom ical ▁clock . ▁ ▁History ▁ ▁Greek ▁and ▁Roman ▁World ▁The ▁first ▁astr aria ▁were ▁mechanical ▁devices . ▁Arch im edes ▁is ▁said ▁to ▁have ▁used ▁a ▁primitive ▁version ▁that ▁could ▁predict ▁the ▁positions ▁of ▁the ▁Sun , ▁the ▁Moon , ▁and ▁the ▁plan ets . ▁On ▁May ▁ 1 7 , ▁ 1 9 0 2 , ▁an ▁arch ae ologist ▁named ▁Val er ios ▁St ais ▁discovered ▁that ▁a ▁l ump ▁of ▁ox id ated ▁material , ▁which ▁had ▁been ▁recovered ▁from ▁a ▁ship w reck ▁near ▁Ant ik y ther a , ▁held ▁within ▁it ▁a ▁mechanism ▁with ▁c og w he els . ▁This ▁mechanism , ▁known ▁as ▁the ▁Ant ik y ther a ▁mechanism , ▁was ▁recently ▁red ated ▁to ▁end ▁of ▁the ▁ 2 nd ▁century ▁B CE . ▁Ext ensive ▁study ▁of ▁the ▁fragments , ▁using ▁X - ray s , ▁has ▁revealed ▁enough ▁details ▁( ge ars , ▁pin ions , ▁c rank ) ▁to ▁enable ▁research ers ▁to ▁build ▁partial ▁rep lic as ▁of ▁the ▁original ▁device . ▁Eng ra ved ▁on ▁the ▁major ▁g ears ▁are ▁the ▁names ▁of ▁the ▁plan ets , ▁which ▁leaves ▁little ▁doubt ▁as ▁to ▁the ▁intended ▁use ▁of ▁the ▁mechanism . ▁ ▁By ▁the ▁end ▁of ▁the ▁Roman ▁Empire , ▁the ▁know - how ▁and ▁science ▁behind ▁this ▁piece ▁of ▁clock work ▁was ▁lost . ▁ ▁Middle ▁A ges ▁and ▁Renaissance ▁The ▁first ▁modern ▁documented ▁astr arium ▁clock