Residual herbicides are routinely applied to control troublesome weeds in pumpkin production. Fluridone and acetochlor, Groups 12 and 15 herbicides, respectively, provide broad-spectrum PRE weed control. Field research was conducted in Virginia and New Jersey to evaluate pumpkin tolerance and weed control to PRE herbicides. Treatments consisted of fomesafen at two rates, ethalfluralin, clomazone, halosulfuron, fluridone, S-metolachlor, acetochlor emulsifiable concentrate (EC), acetochlor microencapsulated (ME), and no herbicide. At one site, fluridone, acetochlor EC, acetochlor ME, and halosulfuron injured pumpkin 81%, 39%, 34%, and 35%, respectively, at 14 d after planting (DAP); crop injury at the second site was 40%, 8%, 19%, and 33%, respectively. Differences in injury between the two sites may have been due to the amount and timing of rainfall after herbicides were applied. Fluridone provided 91% control of ivyleaf morningglory and 100% control of common ragweed at 28 DAP. Acetochlor EC controlled redroot pigweed 100%. Pumpkin treated with S-metolachlor produced the most yield (10,764 fruits ha–1) despite broadcasting over the planted row; labeling requires a directed application to row-middles. A separate study specifically evaluated fluridone applied PRE at 42, 84, 126, 168, 252, 336, and 672 g ai ha–1. Fluridone resulted in pumpkin injury ≥95% when applied at rates of ≥168 g ai ha–1; significant yield loss was noted when the herbicide was applied at rates >42 g ai ha–1. We concluded that fluridone and acetochlor formulations are unacceptable candidates for pumpkin production.

The site of Fort Magnesia, the base hut of a three-man expedition to Payer Harbour, Pirn Island, in the Canadian Arctic, has recently been rediscovered by a party from the Geological Survey of Canada. Erected by Robert Stein's party in summer 1899, and used by them for two years, the hut was almost certainly moved to another site by Robert E. Peary for his over-wintering in 1901–02. Only fragments of the hut now remain. Five graves, probably of Peary's Eskimo helpers, are located nearby.

During the past year, 1969-1970, both the 2-L (Dyck and Fyles, 1962) and 5-L (Dyck et al., 1965) counters were routinely operated. A 1-L counter was finally constructed with acceptable characteristics (see description below) and was operated in July in place of the 5-L counter. The 2-L counter was operated exclusively at 2 atm. The 5-L counter was operated at 1 atm, except for October and November, 1969, when it was operated at 4 atm. The 1-L counter was operated at 1 atm.

The laboratory routinely operates two proportional counters; one 2-L (Dyck and Fyles, 1962) and one 5-L (Dyck et al., 1965). CO2 is used as the counting gas. The 2-L counter is operated mainly at 2 atm. and the 5-L counter mainly at 1 atm. On occasion the 2-L counter is operated at 1 atm. and the 5-L counter at 4 atm. No changes have been made in the CO2 preparation and purification techniques described in previous GSC dating lists (Lowdon et al., 1969; Lowdon and Blake, 1970).

Both the 2-L counter, described in GSC I (Radiocarbon, 1962, v. 4, p. 13–26), and the 5-L counter (GSC IV, Radiocarbon, 1965, v. 7, p. 24–46) were operated routinely during the past year. Approximately half the determinations reported were obtained from each counter. The 2-L counter was operated at 2 atm except for August and September, 1968, when it was operated for the first time at 1 atm. This allowed for the counting of most small samples without the necessity of mixing with dead gas. The 5-L counter was operated at 1 atm, except for the same period when it was operated at 4 atm. Carbon dioxide is used as the counting gas, and both counters are of the proportional type.

The Radiocarbon Dating Laboratory of the Geological Survey of Canada routinely operates two proportional counters; one 2 L and one 5 L. The 2 L counter is operated entirely at 2 atm. and the 5 L counter mainly at 1 atm. On occasion the 5 L counter is operated at 4 atm. Detailed descriptions of these two counters have recently been published (Dyck, 1967a). A I L counter has been fabricated and is now undergoing preliminary testing.

The 2-L counter (GSC I) and the 5-L counter (GSC IV) were operated routinely during the past year. The 5-L counter was operated at 1 atm, except for February-March 1967, when it was operated at 4 atm. Approximately half the determinations reported were obtained from each counter.

Both the 2-L counter, described in GSC I, and the 5-Lcounter (GSC IV) were operated routinely during thepast year. Approximately half of the determinationsreported here were obtained from each counter. The5-L counter was operated mainly at 1 atm.

Both the 2-L counter, described in GSC I, and the 5-L counter (GSC IV) were operated routinely during the past year. Approximately one-half of the determinations reported here were obtained from each counter. The 5-L counter was operated mainly at 1 atm.

For more than a year, age calculations have been carried out monthly by an I.B.M. 1620 computer. If the background, standard, and sample counts during a month conform to statistical laws, they are entered on sheets together with their respective counting times and sample identifications and sent to the computing center for processing.

Most of the determinations reported here were obtained with the 2 L counter described in our first date list (GSC I). All age calculations are based on a C14 half-life of 5568 ± 30 yr and 0.95 of the activity of the NBS oxalic-acid standard, and the ages are quoted in years before 1950. The age errors include: counting errors of sample, background, and standard, the error in the half-life of C14, and an error term to account for the average variation of ±1.5% in the C14 concentration during the past 1100 yr. ‘Greater than’ ages are based on the 4 σ criterion (GSC II).