26 



OKEDEN, ON THE DIATOMACEOUS DEPOSITS OF 



On the Deep Diatomaceous Deposits of the Mud of Mil- 

 ford Haven and other Localities. By Fitzmaurice 

 Okeden, C.E. 



At the time that Mr, Roper's interesting paper on the 

 Thames mud appeared, I was myself engaged in examining 

 the mud of Neyland, which is a creek of Milford Haven and 

 the terminus of the South Wales Railway. At this time, also, 

 we were engaged in making borings for engineering purposes 

 to ascertain the depth of the mud in this creek, and in some 

 places we found that it exceeded 40 and even 50 feet. 



It struck me that it would be interesting to ascertain 

 whether the mud at these great depths was as rich in diato- 

 maceous remains as the surface had proved to be in the living 

 specimens, I accordingly had constructed a simple, but I 

 think effective, apparatus, for the purpose of obtaining the 

 genuine mud from any depth that might be reached, and of 

 insuring that it should be unmixed or uncontaminated with 

 any other deposit. I will, therefore, before laying the results 

 before the reader, desci'ibe the apparatus made use of. I 

 must premise that the usual " boring " apparatus employed 

 for engineering purposes consists essentially of any number of 

 iron rods, which screw one into the other ; to one of these is 

 screwed an auger or a chisel-point, as the case may require. 

 This is inserted into the ground to be tested, and worked 

 round by manual force and downward pressure, length after 

 length of rod being added as the ground is penetrated. In 

 addition, then, to this apparatus, I obtained, first, several 

 lengths of wrought-iron gas-pipe, about an inch in diameter, 

 and each screwing into the other, and also a similar number of 

 iron rods, each a few inches longer than the lengths of gas- 

 piping, and each also screwing into the other ; 

 to the end of one of these lengths of rod is 

 attached a cork of the exact diameter of the 

 gas-pipe, or a trifle larger. This cork is fixed 

 by a washer and nut, as shown in the sketch. 

 Tlie gas-piping should be in lengths of about 

 8 feet each, as this is the most convenient in 

 work : one of these lengths should also be again 

 divided into two parts, which must, however, 

 screw and unscrew ; and this length is to be the 

 one first put into the ground or mud, for reasons 

 which I will presently explain. 



The mode of proceeding is as follows : First, 

 a hole is bored to the required depth — say 20 

 feet — with the usual boring apparatus ; this done, the appa- 



