Beschrijving van een nieuw hulpstuk voor de edelmanboor en enkele opmerkingen over de praktische toepassing van het handboren

An accessory tool is described, which renders the possibility to break a series of lengthening pieces in parts, while the auger remains in the borehole. In this way handborings can be brought down to greater depths then usual (depths over 12 m have been reached), In addition some remarks are given about problems encountered in boring several types of sediment.