MARINE PROTECTIVE ELEMENTS AGAINST MARINE BORERS.

Wood coupons, 3 in. x 4 in. x 34 in. of all sapwood Southern Yellow Pine and all heartwood Douglas Fir comprising 27 systems of various marine protective treatments are being exposed at Boston, Massachusetts, and the samples from Boston showed no evidence of Limnoria attack. At Wrightsville Beach there was a very pronounced attack in systems with initial light retentions of creosote and creosote coal tar 8-16 no. pcf C and 8 no. pcf CCT. The samples with the salt treatments and the combination oil and salt treatments had no Limnoria attack. All specimens identified from Boston were L. lignorum and all specimens identified from Wrightsville Beach were L. tripunctata. Bankia specimens to 45 mm long were observed in both 1 no. ACA and 1 no. CCA treated coupons. The results of the analysis of the oil type preservatives over the 24 month period show a general levelling trend after the initial change in retention for the majority of the samples. The salt retention showed an overall loss in retention for the coupons treated with ACA and an overall gain in the majority of the coupons treated with CCA. Author