First Primary Levelling, England & Wales (1840-60)

Line Name	Total Marks	Marks in DB	Percentage Logged
Carlisle to North Shields *	213	40	18.8%
Carlisle to Sark Bridge	33	1	3%
Darlington to Scarborough (Acklam to Middlesbrough)	15	4	26.7%
Liverpool to Port Carlisle	550	2	0.4%
Newcastle-upon-Tyne to Berwick-upon-Tweed *	217	25	11.5%
Newcastle-upon-Tyne to Crailing *	122	3	2.5%
North Shields to Stockton-upon-Tees *	91	6	6.6%
Selby to Newcastle-upon-Tyne *	250	22	8.8%
York to Bridlington	126	3	2.4%

First Primary Levelling, Scotland (1844-60)

Line Name	Total Marks	Marks in DB	Percentage Logged
Berwick-upon-Tweed to Edinburgh	150	3	2%
Kilmarnock to Glasgow	250	1	0.4%
Stranraer to Glasgow	250	1	0.4%
Tranent to Berwick-upon-Tweed	85	1	1.2%

Second Geodetic Levelling, England & Wales (1912-21)

Line Name	Total Marks	Marks in DB	Percentage Logged
Bromsgrove to Suckley	42	1	2.4%
Bromsgrove to Warwick	44	1	2.3%
Buntingford to Clare	68	1	1.5%
Castor to Wicken	44	1	2.3%
Daresbury to Wrexham	39	1	2.6%
Flax Bourton to Sharpness	32	1	3.1%
Forcett to Wolsingham	27	2	7.4%
Grampound to Troon	20	1	5%
Hemel Hempstead to Buntingford	39	1	2.6%
Hexham to Longhorsley	26	3	11.5%
Hibaldstow to Matlock	69	1	1.4%
Hibaldstow to South Cave	40	1	2.5%
Kirkby Stephen to Penrith	25	1	4%
Liverpool to Daresbury	40	1	2.5%
Longhorsley to Belford	34	2	5.9%
Macclesfield to Daresbury	50	1	2%
Mordington to Belford	16	2	12.5%
Navenby to Hibaldstow	21	1	4.8%
Newlyn (Tolcarne) to Observatory	6	2	33.3%
Newlyn Circuit (2nd)	15	4	26.7%
North Petherton to Dulverton	45	1	2.2%
North Petherton to Flax Bourton	43	2	4.7%
Northallerton to Forcett	38	2	5.3%
Ribblesdale to Kirkby Stephen	23	1	4.3%
Snodland to Wye	2	1	50%
South Shields to Hexham *	158	17	10.8%
Thornford to North Petherton	33	1	3%
Troon to Newlyn (Tolcarne)	24	2	8.3%
Upton Lovell to Flax Bourton	53	1	1.9%
Wetherby to Bulmer	39	4	10.3%
Wicken to Clare	29	1	3.4%
Wolsingham to Hexham *	21	9	42.9%
Wolsingham to Kirkby Stephen	33	2	6.1%
Wye to Guestling	29	1	3.4%

Second Geodetic Levelling, Scotland (1936-52)

Line Name	Total Marks	Marks in DB	Percentage Logged
Buittle to Dalry	14	1	7.1%
Dalry to Thankerton	50	1	2%
Dunlop to Milngavie	30	1	3.3%
Edinburgh to Innerleithen	13	1	7.7%
Edinburgh to Linlithgow	24	1	4.2%
Lairg to Loch Naver	4	1	25%
Lairg to Tain	15	1	6.7%
Laxford Bridge to Durness	4	1	25%
Ledmore to Laxford Bridge	5	1	20%
Necropolis to Dunlop	69	1	1.4%
New Cumnock to Dalry	27	1	3.7%
Ullapool to Lairg	21	1	4.8%
Whittingehame to Edinburgh	22	1	4.5%

Third Geodetic Levelling, England & Wales (1950-68)

Line Name	Total Marks	Marks in DB	Percentage Logged
Belford to Longhorsley	36	2	5.6%
Bromsgrove to Warwick	38	1	2.6%
Buntingford to Great Linford	57	1	1.8%
Carmarthen to Haverfordwest	42	1	2.4%
Church Stretton to Bromsgrove	67	1	1.5%
Clare to Wicken	31	1	3.2%
Cockermouth to Wetheral	46	1	2.2%
Countisbury to North Petherton	44	1	2.3%
Cowbridge to Bishopston	40	1	2.5%
Croydon to Buntingford	67	1	1.5%
Daresbury to Liverpool	30	1	3.3%
Dulverton to North Petherton	38	1	2.6%
Flax Bourton to Sharpness	39	1	2.6%
Flax Bourton to Upton Lovell	54	1	1.9%
Forcett to Northallerton	44	2	4.5%
Hatfield Peverel to Buntingford	41	1	2.4%
Haverfordwest to Cardigan	71	1	1.4%
Haverfordwest to Carmarthen	84	1	1.2%
Hexham to Hawick	71	7	9.9%
Hexham to Wolsingham	38	10	26.3%
Hibaldstow to Navenby	31	1	3.2%
Immingham to Hibaldstow	22	1	4.5%
Isle of Thanet to Guestling	56	1	1.8%
Kirkby Stephen to Ribblesdale	40	1	2.5%
Longhorsley to Hexham	35	4	11.4%
Macclesfield to Daresbury	46	1	2.2%
Madron to Troon	19	2	10.5%
Maybush Circuit	11	1	9.1%
Maybush to Winchester	22	1	4.5%
Mickleby to Longhorsley	115	16	13.9%
Mordington to Belford	24	2	8.3%
Newlyn Circuit (3rd)	21	5	23.8%
North Petherton to Flax Bourton	43	2	4.7%
Northallerton to Mickleby	50	2	4%
Oswestry to Daresbury	63	1	1.6%
Penhow to Cowbridge	39	1	2.6%
Penrith to Kirkby Stephen	36	1	2.8%
Snodland to Isle of Thanet	79	1	1.3%
Snodland to Wye	45	1	2.2%
South Cave to Hibaldstow	52	1	1.9%
Troon to Boscastle	68	1	1.5%
Troon to Grampound	23	1	4.3%
Tynemouth Loop	7	5	71.4%
Wasdale to Cockermouth	36	1	2.8%
Wetheral to Hexham	42	5	11.9%
Wetherby to Bulmer	42	3	7.1%
Wicken to Castor	49	1	2%
Wolsingham to Forcett	43	2	4.7%
Wye to Guestling	35	1	2.9%

Third Geodetic Levelling, Scotland (1956-68)

Line Name	Total Marks	Marks in DB	Percentage Logged
Dalry to Ayr	39	1	2.6%
Dalry to Buittle	20	1	5%
Edinburgh to Linlithgow	36	1	2.8%
Edinburgh to Whittingehame	33	1	3%
Glen Cluanie to Glen Moriston	30	1	3.3%
Glen Moriston to Loch Tarff	14	1	7.1%
Glen Moriston to Scourguie	30	1	3.3%
Gourock to High Boydston	29	1	3.4%
High Boydston to Ayr	40	1	2.5%
High Boydston to Dunlop	18	1	5.6%
Laxford Bridge to Durness	26	1	3.8%
Ledmore to Laxford Bridge	40	1	2.5%
Milngavie to Bowling (via Govan)	35	2	5.7%
Rosyth to Edinburgh	23	1	4.3%