can be keyed into memory the speed of delivery of the wrapping material 54 to the baling chamber 26 is approximately that of the belts 28 which is determined by a speed sensor 92 located for determining the speed of rotation of the lower rear belt support roll 30 with this information the microprocessor 80 calculates how long after receiving the signal resulting from closure of the switch 88 that the marking device cylinder 66 should be actuated to apply the visual marker 76 to the wrapping material 54 referring now to fig4 and 5 there is shown a bale 100 wrapped with one complete layer of wrapping material 54 and including a bottom region 94 where a second layer of the wrapping material 54 is applied this is the disposition of the bale for storage with the extra layer of material 54 affording extra protection to the bale from ground water or soil moisture if after being discharged from the baler 10 the bottom region 94 is not at the bottom of the bale the operator can easily determine this unwanted position of the bale by seeing the location of the visual marker 76 a correct positioning of the bale 100 can then be achieved by using a loader or other appropriate equipment to manipulate the bale 100 at a storage site so that the visual marker 76 appears at the top of the bale it should be understood that other ways of marking the bale 100 are possible for example a dye sprayer could be provided at the front of the baler 10 for applying a marking dye to a desired location of the circumference of the bale 100 prior.