Item 10: General William Holmes diary, 23 August 1914-22 February 1915 - Page 257
9th January 1915.
On Tuesday last, 5th inst., Lieut. Comm. Bracegirdle, R.A.N., Lieut. Goadby, R.A.E., and Lieut. Marsden, M.G.S., went out on the Bitapaka road and blew up one of the mines which we passed over on 11th Septr.
They placed a detonator at the end of the tube with about 4ft. fuze; the explosion that followed could be heard distinctly at Herbertshohe about 4 miles away in a direct line.
I went out the next day, Wednesday, 6th inst., with a party to fill in hole made by the explosion, and found a hole 27 ft. long, 15ft wide and 8 ft. deep, but they had only exploded one of the mines, so I followed the wires of the first mine from a log at the side of the road, by digging a trench across the road, to the mine, which consisted of an iron tube 21ft. long, 12 in. in circumference packed loosely with 'Nobel's' dynamite. On top of the tube were placed between 2 and 3 cwt. of bolts and nuts, and above this was packed with solid blocks of coral.
I carefully removed the coral, bolts and nuts and had the mine carried into the bush; Lieut. O.W. Gillam, R.A.N.R., S.W. Cameron, R.A.N.R., arrived on the scene, and I had the mine exploded with a detonator and about 3 ft. of fuze. The explosion was enormous, and small pieces of pipe were picked up 200 yards away; it made a very large hole, knocked over trees, and made a black cloud 200 ft. high, with a circumference of about 600 ft., within which it was absolutely dark for some minutes. One could not see their hand held up in front of one's face. The report was distinctly heard at Herbershohe.
The mines were 75 feet apart, placed along the road (not across). I attach a rough sketch of how they were laid; if they had let them off when we were over them, we would not have known anything about it, there being enough explosives to blow a whole battalion to pieces.
Midshipman William took a photograph of the one I unearthed as it lay in the trench. If possible I will send you a copy of it.
(Sgd.) T.A. Bond, Lieut. R.A.N.R.