Under a Dark Sky
It’s mid-October in Scotland. The Sun is shining, but only feebly now, being long past the glory days of summer. A few white fluffy clouds pepper an otherwise cobalt blue sky, and the wind has all but abated. The rain-soaked trees glisten in the sunshine, and the ground makes a crunching sound underfoot as boots wade through a thick deposit of fallen leaves to best position the telescope for a spot of daylight observing. The telescope, a small portable achromatic refractor, has a doublet lens composed of crown and flint glasses with an 80-mm aperture and 400-mm focal length. It sits on a sturdy but lightweight aluminum tripod equipped with good slow-motion controls. The metal dust cap is unscrewed, allowing the lens to taste the cool, ambient air. The retractable dew shield is extended to keep condensations at bay as well as acting as an effective tool against peripheral glare. Sighting along the top of the tube, I insert a low power eyepiece and aim the telescope at the topmost boughs of a beech tree about 50 yards in the distance, and looking though the ocular, i bring the image into sharp focus by slowly turning the single-speed focusing wheel.