Calculations – Thomas Marshall – 1 Apr 1763

A Calculation of the Yearly Value of the Lead Mines comprized in Sir Walter Blackett’s Lease for Lives according to Mr Richmond’s Conception 20th August 1762 (in his Observations upon Mr Halhead’s Calculation of the Yearly Value of the Lead mines granted to him by the Lease for Years) and according to the Terms of the only two Tacks lett, Viz. Scraithhead and Pike Stone.



                                           Bings h 

The Whole Quantity of Ore got under        49987 0 1/2

said Lease for Lives in 14 Years 1746 

and 1759, both inclusive, being 



The Quantity in one Year will be about	      3570 2



Deductions

The Bishop’s 1/9 Lott nearly                 396 3

                                            3173 3 at 50s £7934  7  6



                                       Scraith head    Pike Stone

The Rector’s 1/10 after the Bishop’s 

   1/9 is taken out       317 1 1/2 a 50s  793  8  9	

                                                     at 33s 5891  6  6

Raising 3570B 2h                    a 30  5355 15	

Money Rent Reserved by the Lease           150               150

Total of Deductions besides the 

   Bishop’s Lott                         £6299  3  9       £6041  6  6



One Year’s Value (exclusive of the 

   Profits by the Composition for the

   Bishop’s Lott and the Rector’s Tenth)  1635  3  9        1893  1  -

One Year’s Profit by the Bishop’s Lott 

   Only                                    670 10            670 10  -

                                          2305 13  9        2563 11  -



N.B.  N. Halhead is of Opinion that the Quantity of Ore raised Yearly under said Lease for Lives from the Year 1750 (when the Lease in Being was granted) to the present time considerably exceeds 3570B[ings]  2H[orse] and that the Medium Price for that time also considerably exceeds £12 10 p Ton for Lead, which Answers to 50s  p Bing for Ore .