ANTIQUE FELT & TARRANT COMPTOMETER MECHANICAL ADDING MACHINE CALCULATOR MODEL H
Item History & Price
| Reference Number: Avaluer:2854162 |
Felt & TarrantComptometer Model HMY RESEARCH SUGGESTSTHAT THIS IS A MODEL H10/11 columns, Sterling currency APPEARS TO BE IN GOOD WORKING ORDER.tHE CLEARING HANDLE WORKS EASILY, ALL THE BUTTONSPUSH DOWN AND REGISTER AND THE MACHINE ADDSDimensions:9-1/2"W x 15"D x 6"H Weight: 21 pounds ABOUT 9 KILOSManufactured: Chicago, USA, 1920-1926A 10-column Model HComptometer for Sterling currency, with the classic "Comptometer"name embossed into the front AND BACK of the case.The Model H made...significant changes to the clearing mechanism to further reduce the chance oferror. Operators making perhaps 200, 000 keystrokes and 3000 clearings per daywould sometimes fail to clear the machine before starting a new calculation, and would be unaware of their mistake. The Model H Comptometer introduced a"start-from-clear" signal which provided threee separate indications- visual, audible, and tactile. The clearing handle was relocated to a moreconvenient position near the front of the machine, and needed only to be drawnlightly forward and released. After clearing, the zeros in the register wereoffset slightly to give a visual confirmation of the machine's state. The firstkeystroke of the next calculation required a firmer pressure, corrected thezeros, and rang a small bell, thus providing three separate signals to verifythat the calculation was starting from clear.Felt & Tarrantmade much of the term "Enforced Accuracy" in their advertising, as itwas impossible to be unaware of an operating error.The mechanical changesneeded to provide the clearing signals are described in US Patent 1357748, filed by engineer J.A.V.Turck in 1919. The escapement mechanism was redesignedand mounted in a hinged sub-frame, which was controlled by two over-centretoggle mechanisms triggered alternately by the keys and the clearing handle.The sub-frame could be removed relatively easily, which greatly simplifiedcleaning and adjustment. The front of the case was lengthened by half an inchto accommodate the new mechanism.THE PHOTOGRAPHS FORM PART OF THE DESCRIPTION
PROVENANCE:THIS OBJECT IS PART OF A COLLECTION RELATING TO THE HISTORY AND DEVELOPMENT OF CALCULATING DEVICES ASSEMBLED BY ASSOC PROFESSOR ALLAN BROMLEY OF SYDNEY UNIVERSITY, COMPRISING MATHEMATICAL INSTRUMENTS, SLIDE-RULES, MECHANICAL AND ELECTRONIC CALCULATORS, ELECTRONIC ANALOGUE COMPUTERS, COMPUTER COMPONENTS, KIT COMPUTERS, EDUCATION COMPUTERS, AND ASSOCIATED EPHEMERA.ALLAN BROMLEY WAS A LECTURER AND RESEARCHER AT THE UNIVERSITY OF SYDNEY BASSER DEPARTMENT OF COMPUTER SCIENCE FROM 1978 UNTIL HIS UNTIMELY DEATH IN AUGUST 2002. HE SPECIALISED IN COMPUTER ARCHITECTURE, COMPUTER LOGIC AND IN PARTICULAR THE HISTORY OF COMPUTING. HE WAS REGARDED AS THE WORLD AUTHORITY ON CHARLES BABBAGE'S CALCULATING ENGINES (INSTIGATING THE BUILDING OF THE DIFFERENCE ENGINE NO.2 AT THE SCIENCE MUSEUM LONDON) AND THE ANTIKYTHERA MECHANISM AND HAD EXTENSIVE KNOWLEDGE OF CALCULATORS, ANALOGUE COMPUTERS, LOGIC, STEREOPSIS, TOTALISATORS, CLOCKS AND TIME KEEPING AND MECHANICAL ENGINEERING.POSTAGE:FOR DOMESTIC CUSTOMERS, ALL OUR PARCELS/ITEM WILL BE POSTED BY REGULAR POST UNLESS OTHERWISE REQUESTED AND THERE WILL BE AN ADDITIONAL CHARGE. COMBINED POSTAGE IS PROVIDED. PAYMENT: AUSTRALIAN CUSTOMERSWE ACCEPT PAYMENT BY PAYPAL. LOCAL PICK UP IS WELCOME. INTERNATIONAL CUSTOMERSWE ACCEPT PAYMENT BY PAYPAL. WE DO NOT ACCEPT INTERNATIONAL MONEY ORDERS OR US CHECKS. FREE COLLECTION IS AVAILABLE, CONTACT US FOR DETAILS (SYDNEY) (7 DAYS)ITEMS CAN BE COLLECTED AFTER THE AUCTION OR SALE IS COMPLETED. TERMS AND CONDITIONS:PROMPT PAYMENT IS EXPECTED. "BUY IT NOW" IS PAY NOW BY PAYPAL. CONTACT MUST BE MADE WITHIN 2 DAYS OF THE CLOSE OF AUCTION OR SALE. ALL PAYMENT MUST BE RECEIVED WITHIN 3 DAYS OF CLOSE OF AUCTION OR SALE, UNLESS OTHER ARRANGEMENTS HAVE BEEN MADE. THE ITEM WILL BE POSTED AS SOON AS MONEY IS RECEIVED AND CLEARED. REGISTERED POST IS AVAILABLE, EMAIL FOR A QUOTE. ANY QUESTIONS OR PROBLEMS PLEASE CONTACT US. WE LEAVE FEEDBACK ON EVERY TRANSACTION A FULL REFUND WILL BE GIVEN IF ITEM IS INCORRECTLY DESCRIBED WHEN BUYING MULTIPLE ITEMS:IF YOU HAVE PURCHASED MULTIPLE ITEMS FROM US, PLEASE DO NOT AUTOMATICALLY PAY THE CALCULATED CHARGES PER ITEM, BUT RATHER CONTACT US POST-SALE SO THAT WE CAN CALCULATE THE ACTUAL AND MUCH-REDUCED COST OF THE COMBINED SHIPMENT. IF YOU HAVE PURCHASED AN ITEM FROM US, BUT ARE STILL BIDDING OR WISHING TO BID ON OTHER OF OUR ITEMS, PLEASE ADVISE US AND WE WILL DEFER SETTLEMENT ON THE PURCHASED ITEM(S) FOR UP TO TEN DAYS MAXIMUM SO YOU CAN SEE WHETHER YOUR OTHER BID WAS SUCCESSFUL, AND THUS MAKE SIMILAR SAVINGS ON CONSOLIDATED SHIPPING OF THE TWO OR MORE ITEMS. YOU MAY, OF COURSE, ELECT TO SIMPLY PAY FOR EACH ITEM AS PURCHASED WITH ITS INDIVIDUAL POSTAGE/SHIPPING COST.EBAY BACK BOOKSHELVES
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PROVENANCE:THIS OBJECT IS PART OF A COLLECTION RELATING TO THE HISTORY AND DEVELOPMENT OF CALCULATING DEVICES ASSEMBLED BY ASSOC PROFESSOR ALLAN BROMLEY OF SYDNEY UNIVERSITY, COMPRISING MATHEMATICAL INSTRUMENTS, SLIDE-RULES, MECHANICAL AND ELECTRONIC CALCULATORS, ELECTRONIC ANALOGUE COMPUTERS, COMPUTER COMPONENTS, KIT COMPUTERS, EDUCATION COMPUTERS, AND ASSOCIATED EPHEMERA.ALLAN BROMLEY WAS A LECTURER AND RESEARCHER AT THE UNIVERSITY OF SYDNEY BASSER DEPARTMENT OF COMPUTER SCIENCE FROM 1978 UNTIL HIS UNTIMELY DEATH IN AUGUST 2002. HE SPECIALISED IN COMPUTER ARCHITECTURE, COMPUTER LOGIC AND IN PARTICULAR THE HISTORY OF COMPUTING. HE WAS REGARDED AS THE WORLD AUTHORITY ON CHARLES BABBAGE'S CALCULATING ENGINES (INSTIGATING THE BUILDING OF THE DIFFERENCE ENGINE NO.2 AT THE SCIENCE MUSEUM LONDON) AND THE ANTIKYTHERA MECHANISM AND HAD EXTENSIVE KNOWLEDGE OF CALCULATORS, ANALOGUE COMPUTERS, LOGIC, STEREOPSIS, TOTALISATORS, CLOCKS AND TIME KEEPING AND MECHANICAL ENGINEERING.POSTAGE:FOR DOMESTIC CUSTOMERS, ALL OUR PARCELS/ITEM WILL BE POSTED BY REGULAR POST UNLESS OTHERWISE REQUESTED AND THERE WILL BE AN ADDITIONAL CHARGE. COMBINED POSTAGE IS PROVIDED. PAYMENT: AUSTRALIAN CUSTOMERSWE ACCEPT PAYMENT BY PAYPAL. LOCAL PICK UP IS WELCOME. INTERNATIONAL CUSTOMERSWE ACCEPT PAYMENT BY PAYPAL. WE DO NOT ACCEPT INTERNATIONAL MONEY ORDERS OR US CHECKS. FREE COLLECTION IS AVAILABLE, CONTACT US FOR DETAILS (SYDNEY) (7 DAYS)ITEMS CAN BE COLLECTED AFTER THE AUCTION OR SALE IS COMPLETED. TERMS AND CONDITIONS:PROMPT PAYMENT IS EXPECTED. "BUY IT NOW" IS PAY NOW BY PAYPAL. CONTACT MUST BE MADE WITHIN 2 DAYS OF THE CLOSE OF AUCTION OR SALE. ALL PAYMENT MUST BE RECEIVED WITHIN 3 DAYS OF CLOSE OF AUCTION OR SALE, UNLESS OTHER ARRANGEMENTS HAVE BEEN MADE. THE ITEM WILL BE POSTED AS SOON AS MONEY IS RECEIVED AND CLEARED. REGISTERED POST IS AVAILABLE, EMAIL FOR A QUOTE. ANY QUESTIONS OR PROBLEMS PLEASE CONTACT US. WE LEAVE FEEDBACK ON EVERY TRANSACTION A FULL REFUND WILL BE GIVEN IF ITEM IS INCORRECTLY DESCRIBED WHEN BUYING MULTIPLE ITEMS:IF YOU HAVE PURCHASED MULTIPLE ITEMS FROM US, PLEASE DO NOT AUTOMATICALLY PAY THE CALCULATED CHARGES PER ITEM, BUT RATHER CONTACT US POST-SALE SO THAT WE CAN CALCULATE THE ACTUAL AND MUCH-REDUCED COST OF THE COMBINED SHIPMENT. IF YOU HAVE PURCHASED AN ITEM FROM US, BUT ARE STILL BIDDING OR WISHING TO BID ON OTHER OF OUR ITEMS, PLEASE ADVISE US AND WE WILL DEFER SETTLEMENT ON THE PURCHASED ITEM(S) FOR UP TO TEN DAYS MAXIMUM SO YOU CAN SEE WHETHER YOUR OTHER BID WAS SUCCESSFUL, AND THUS MAKE SIMILAR SAVINGS ON CONSOLIDATED SHIPPING OF THE TWO OR MORE ITEMS. YOU MAY, OF COURSE, ELECT TO SIMPLY PAY FOR EACH ITEM AS PURCHASED WITH ITS INDIVIDUAL POSTAGE/SHIPPING COST.EBAY BACK BOOKSHELVES
02000
