Introduction
"This series of workbooks (Coalbrookdale A, B, C, etc) is concerned with the costs of production of iron at Coalbrookdale.   "
"Data has been collected from the original accounts,   Shropshire Records and Research, 6001/329-331 and Ironbridge Gorge Museum, ms. CBD 59.82.5.   These are the complete journals (known incorrectly as stockbooks) and cash books for the Coalbrookdale Company covering their whole business at Coalbrookdale.    Unfortunately the ledgers that were prepared from these do not survive.   The journals have a few pages missing,  most notably at the beginning of the second volume of it."
"The object has been to calculate the cost of production at the door of the ironworks.  As a matter of policy therefore the costs charged to the warehouse and pig yard have been omitted,  as being sales and distribution costs.   Those attributed to the forge warehouse have also been omitted,  but some distribution costs for bar iron were charged to the forge and these do appear.  "
"In collecting data, work concentrated on the various production facilities of the Company,  two blast furnaces,  three air furnaces,  and (from 1720) the middle forge.   The blast furnaces and Upper Air Furnace were in use almost continuously.   The New Air Furnace (abbreviated as AFN) was regularly used when one of the blast furnaces was out of blast,  but the Lower Air Furnace was hardly used at all except in the first few years.  "
"Figures for 'General Charges' have only been collected where they were mixed up with entries relating to works.  Accordingly all coal charged to General Charges has been collected, and all cash book payments charged to them,  but other General Charges may well not have been extracted.  Some data concerning the forge was collected as part of the main process,  principally the purchase of pit-coal from the same series of entries in the journal as other parts of the business and items paid for immediately from the cash book,  but some data was collected in a separate exercise into a separate Coalbrookdale Forge workbook.   Accordingly the entries in books F & G concerning the forge do not represent more than part of its costs.  The reasons for this are directly related to the way the information appears in the account books."
"Data has not been systematically rechecked against the original,  since its collection was itself an enormous task,  but selected items have been rechecked,  particularly where there seemed to be an inconsistency in what had been entered.   "
"For reasons of space,  formulae for calculating the cost from the data have not been included in the worksheets.  Instead a series of macros have been written,  which carry out calculations and place the results in the appropriate column. Other macros rearrange the data,  so that data from the journal and the cash book are combined (file B),  sorted by works etc. (file C),  sorted by commodity etc. (file D) and so on.   "
"The vast bulk of the entries collected from the journals are of two kinds:  firstly the carriage,  royalty,  and (for certain suppliers only) getting of coal, and secondly a series of entries that have been labeled 'various charges'.   The latter is mostly the payment of wages for coking coal, moulding pots etc. and carriage and royalty of limestone and sand. Details have not been extracted of sand,  nor of any other amounts appearing in this section,  nor up to a certain point was the amount of limestone royalty. The processing instructions have however been written, so that the limestone royalty is added to its carriage and expenses whose nature has not been extracted appear in file D under sundry.   This sundry category also includes certain miscellaneous expenses appearing in the journals as separate items, such as hides (for the bellows).   "
"Though forge costs appearing in the cash book have been extracted as part of the main data collection exercise together with its (mineral) coal costs,  other forge costs appearing in the Journals were extracted separately,  as were sales figures for the pig yard.   "
"Running the whole computational process is a very long winded affair.   It is achieved by running MasterDriverMacro in this workbook.  This includes instructions to save the active workbook at various points,  and also to preserve the previous version of each workbook before starting to amend it.   This also runs various other macros in the correct order and may include some steps that are redundant unless earlier data has been altered. The process can also be initiated at a later stage using MasterDriverD macro in Coalbrookdale D."
"Years in the original end at 24 March in accordance with contemporary practice.   In collecting data this was altered to the style 1724/5 for the period 1 Jan. to 24 Mar.  From file D dates are given in modern form,  but the date and year have been placed in separate columns,  since the version of EXCEL used seems not to be able to cope with a date before 1900,  or at last fails to recognise it as being a date.   "
"The instructions for creating workbook D from workbook C are particularly complicated and mainly operate by means of a subroutine which copies a value from a particular place in some cases if the item is not zero and in others if there is a particular prompt word in another column.   It has been necessary to add additional conditions to some of these instructions.  In the following book (E) certain further adjustments are made:  an extra column is added and  in order to cover the situation where an air furnace was idle throughout a year,  blank lines (with nothing but the date and works have to be inserted at certain points.   Additionally pig iron and scrap transferred between the works are priced.  Figures altered or added by this means have a light yellow background"
"The prices used are ?2 per ton for sculls,  ?5 for spoilt castings (such as 'tunnelware' and 'halfware') at ?5 per ton,  and for coke pig iron a price collected from another workbook,  called pig yard. The price charged to customers was not systematically collected,  but enough examples were noted to provide a price series.  Prices charged to Thomas Goldney of Bristol have generally been  preferred to the less frequent sales to other customers.   This conforms to the pig iron price charged in the accounts on a few occasions for transfers to the forge;  however such transfers were usually made without any price being attributed to them.   "
"In book F the data is totalled by year,  with a year end of 30 June,  save that the final 'year' runs on to the following Michaelmas when a new Company took over the business.   No adjustment has been made for data that might have appeared on pages that are missing from the journals. This problem is most severe at the beginning of the second volume.  "