APPENDIX I

RECORD OF HYDROLOGICAL TESTS

NOTES

No difficulty was experienced in observing dye by artificial light. It was noted that the colour was most distinct where the bed of the stream was of black gravel. Conversely, the dye was most difficult to see where the water was shallow and running over clean limestone.

The quantities of fluorescein used were in nearly all cases adequate. Of the few negative tests carried out, in only two cases was failure probably due to insufficient fluorescein. In the case of the other dyes there were several negative tests due to this cause and it became clear that the alternative dyes are of practical use only in the most favourable circumstances or in cases where a number of minor tests were carried out simultaneously.

A number of negative tests of little value have been omitted from the following record.

DIARY

Minor tests with various dyes proved that three small streams flowing from Leck Fell and sinking before reaching Ease Gill debouched into Ease Gill between Oxford Pot and Slit Sinks after travelling short distances underground.

17th December 1950. 1 oz dye placed in Borehole Sink. Observed one hour later issuing from choke at end of Green and Smelly passage and flowing down full length of passage. Streams rather low.

28th January 1951. 2 ozs dye placed in Corner Sink at zero hour and a further quantity at zero plus thirty minutes. Observed at zero plus forty five minutes issuing from Trident Passage into Pierce's Passage. Still visible three hours later in Lower Pierce's Passage.

11th February 1951. Negative tests. 1 oz dye placed in Boundary Pot and not observed in Thackray's passage up to three hours later. Blue dye placed in Slit Sink not seen in Main drain. Heavy water flow.

4th March 1951.
(a) 1 oz dye placed in Gelder Hole at 1.05 pm. Observed at Showerbath inlet in Showerbath passage at 1.50 pm. Quickly became vivid and had passed peak concentration by 2.05 pm. Colour obvious in Lower Spout Passage at 3.10 pm and seen faintly beyond Spout Hall at 6.00 pm.

(b) 2 oz Rhodamine placed in Slit Sinks in three parts at 12.30, 2.30 and 3.00 pm. 1 oz Rhodamine placed in Cow Dub in three parts at 12.00, 1.00 and 2.00 pm. No dye observed underground up to 6.00 pm. Heavy water flow.

24th March 1951. 3 oz dye placed in main inlet inside Boundary Pot (presumed to be from Ease Gill stream bed, which is within a few feet of the inlet) at 12.30 pm. Main Drain clear at 3.00 pm, but Thackray's Passage stream strongly coloured on arrival of party at Holbeck Junction at 3.30 pm. Colour persisted in Thackray's Passage until after 7.00 pm. Fairly heavy water flow.

26th March 1951.
(a) 1 oz dye at 12 noon and 1 oz at 12.30 pm placed in Innominate Sink. Observed issuing from inlet at top end of Broadway at some time around 1.00 pm.

(b) 2 oz dye at 12.15 pm and 1 oz at 12.30 pm placed in Slit Sinks. Seen between 2.00 pm and 4.00 pm issuing from large inlet at head of Green and Smelly passage. Heavy water flow.

8th April 1951.
(a) ¼ oz dye placed in Innominate Sink at 1.30 pm precisely. Colour appeared at foot of boulder slope at upper end of Broadway at 1.40 pm precisely.

(b) 1 oz dye placed in Blind Pot at 12.45 pm and 1 oz placed in Dolly Tubs gully above Cow Dub at 1.00 pm. Observed at Toadstool junction issuing from Butterfield's Passage at 2.05 pm.

(c) Part of Ease Gill stream diverted down Rosy Sinks and 3 oz red dye introduced at 1.05 pm and 3 oz at 1.40 pm. Stream issuing from opening in Broadway a few yards above Oxford Circus clear at 1.20 pm and 1.50 pm. Faint colouring seen in Mushroom Passage entrance near Toadstool Junction at 2.10 pm. Mushroom Passage stream vivid red at 2.15 pm but almost clear again at Oxford Circus at 2.20 pm. Heavy water flow.

22nd April 1951.
(a) 4 oz dye placed in water trickle at Top Sink at 12.00 noon and 1.00 pm. Observed flowing through Bradshaw's Passage during the afternoon. Inlet at Limerick Junction clear.

(b) At 4.30 pm ½ oz dye placed in stream feeding Innominate Sink 200 yards above sink, where leakage was suspected. Appeared at first rising above Cow Dub at 5.40 pm. Very distinct at 6.00 pm. Flow below normal.

13th May 1951. Very dry conditions. It was noted that water issuing from a small bedding cave in Leck Fell side of Ease Gill a few yards above Oxford Pot was totally engulfed into joints in the bed of Ease Gill. ½ oz dye placed therein observed in Spout Hall. Snake clear. Water assumed to issue from the Showerbath.

30th September 1951. Dye placed in Pool Sink and observed issuing from a small inlet above the lower water falls in "T-piece" Passage.

4th November 1951. Flood conditions. Tests on a small stream flowing from Leck Fell almost opposite Oxford Pot. 2 oz dye introduced 200 yards above final sink. Bedding cave a few yards above Oxford Pot coloured after a few minutes and Gelder Hole coloured after 30 minutes.