yesterday, 99° at 3 p. m. . . . Saw the nighthawks fly low and touch the water like swallows, at Walden.
June 21, 1860. Having noticed the pine pollen washed up on the shore of three or four ponds in the woods lately, at Ripple Lake, a dozen rods from the nearest pine, also having seen the pollen carried off visibly half a dozen rods from a pitch pine which I had jarred, and rising all the while when there was very little wind, it occurred to me that the air must be full of this fine dust at this season, that it must at times be carried to great distances, and that its presence might be detected remote from pines by examining the edges of pretty large bodies of water where it would be collected on one side by winds and waves from a large area. So I thought over all the small ponds in the township in order to select one or more most remote from the woods or pines, whose shores I might examine and thus test my theory. I could think of none more-favorable than this little pond only four rods in diameter, . . . in John Brown's pasture, which has but few pads in it. It is a small round pond at the bottom of a hollow in the midst of a perfectly bare, dry pasture. The nearest wood of any kind is just thirty-nine rods distant northward, and across a road from the edge of a pond. Any other wood
