Calculating Defoe's Garden Area
The 1848 Tithe Map
The Tithe map of the Church Street terrace.
The 1868 Ordnance Survey Map
The 1894 Ordnance Survey Map
Plot 522 on 1848 Tithe Map and Lot 88 on the 1868 map
This is the shape of lot 522 on the 1848 Tithe map, with a large lawn surrounded by a border and a garden. It is called lot 88 on the 1868 map. 


What is the total area? To find this the shape must be simplified and the following drawings show one way of doing this. The plot has been labeled ah in a clockwise direction. 

Fig 1: The Simplified Garden Plan abcdefgh
Fig 2: The shape is very irregular, with projecting pieces and indentations around it. efg is a projecting triangle. This projection needs to be drawn into the main body of the garden.
Method.
Project the base line hg to j. Join eg. Draw fk parallel to eg. Join ek.
Fig 3: Consider the lower half of Fig. 3 only at the moment. efkg is the same as before. Line ek has been joined to create two triangles efx and xkg. These have been tinted.
Imagine eg as the base and efkg as a four sided figure. Inside it are two triangles fge and kge. They have the same base line eg. fk is parallel to eg, so the vertical heights of the two triangles are equal. Triangle exg is common to both. Therefore they (efx abd xfg) must have the same area.
Fig 4: Triangle efx has slid down to become xkg and the projecting point f has been removed. The base line hg has been extended to k. 

Fig 5: Next consider the Upper half of Fig, 5. Here bcd is a triangle cutting into the shape. It needs to be filled in to smooth the shape.
Join bd. Draw lc parallel to bd. Join ld. lbc and ldc have the same base line lc and the same vertical height, so they are the same area. Triangle lby can be slid down to cyd so filling some of the indentation. In this case the line ab has been shortened to al.
Fig 6: The new shape of the original plot is now aldekh.
Fig 7: The existing figure is aldeh. Consider the lower half. dek is a slight indentation which needs to be smoothed out. Join dk. Draw em parallel to dk. join dm. dek has been filled in to form dm and the corner is now dmh. The base hk has shortened to hm.
Fig 8: The new shape is aldmh.


Fig 9: Consider the upper half. ald is a projecting corner to be smoothed out. Extend ha to n. Join ad and draw ol parallel to ad. azo = zld in area.
Fig 10: The new shape is odmh.
Fig 11: odm projects from the triangle and must be smoothed out. Extend hm to q. Join om and draw dp parallel to om. Join op.
Fig 12: The irregular shape of lot 522 has now been reduced to the simple triangle oph, of the same area.
Fig 13: Triangle oph has the base ph. Drop a perpendicular or from o to the base. This is the vertical height of the triangle. Bisect the vertical height and draw rectangle stph.
Fig 14: This can now be measured and the area of lot 522 calculated. It turns out that this area equal almost exactly 4 Acres. 
All the houses built between Hussey's Lane and the backs of the old houses in the High Street and between the backs of the houses in Church Street and Pawnbroker's Lane ( Kynaston Road ) were built on Defoe's Garden.
Defoe's meadow.
This is drawn at half the scale of the Defoe's garden as it was so large.
END OF CALCULATING DEFOR GARDEN
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1868 defoe garden 750
KIEITH
WILL YOU PLEASE RESCAN THIS TO GET A BETTER COPY. I WOULD LIKE TO PRINT THE SECOND MAP ONLY. PERHAPS IT COULD HAVE A BORDER ROUND IT AND BE COLOURED TO STRESS IT.
CAPTION  These streets were all built on Defoe's garden.
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