which alterations Reductions or Additions shall not vacate or vary this Contract but in Case of any
Alteration or Alterations in addition to the Quantity of Work and materials described set forth and
mentioned in the Schedule hereunto annexed the sd James Tyson< no role > shall be allowed and paid such
Sum & Sums of Money for the same as the sd additional work and materials shall deserve
such work & materials to be Estimated and valued by the sd Surveyor for the time being to the sd
Comrs. Or if any alteration or alterations shall be made in the sd Plan in dimunition of the
Quantity of work & materials described set forth & mentioned in the sd Schedule a reasonable
deduction shall be made from the said Sum of £165 herein Covenanted to be paid to him
the sd James Tyson< no role > all such Estimations Valuations Allowances deductions & admeasuremts.
to be made by the sd Surveyor for the time being to the sd Comrs. whose determination therein
shall be bending & Conclusive on all parties or if such alterations in additions to the sd Plan

80

shall require a different sort of work than what is mentioned in the sd. schedule than the sd.
James Tyson< no role > shall be paid such price for such different kind of work as the same shall
deserve such peice to be Estimated by the sd Surveyor whose determination shall be binding
and Conclusive or if in the Execution of the sd Plan a different sort of work & Materials
shall be required than what is mentioned in the sd Schedule and which work & materials
shall be of such kind as cannot be ascertained in point of value but by time or the day an account
in writing of such work & materials shall be returned by the sd James Tyson< no role > to the sd Surveyor once
after in every fortnight & the sd James Tyson< no role > shall be allowed such price for such work