The Motions of High-Latitude Hydrogen Clouds

We have obtained the solar motion with respect to 268 well-resolved (in velocity) 21-cm hydrogen clouds with galactic latitudes numerically greater than 20 and declinations greater than 400. The result is a velocity of 21?2 + 0?9 km toward t = 52?5 + 2?9, b = +210.3 + 206 where the uncertainties are standard errors. The mean distance times the galactic-rotation constant is 6.8 + 2.1 km sec-', and the apparent longitude of the center of rotation is 346?5 + 4?0. The residual radial velocities are well fitted by an exponential distribution function of the form P(v) = (2 -1 exp (- IvI/ where the maximum-likelihood principle gives 5.0 km for ,;. The average distance of hydrogen clouds in the latitude range does not follow a cosecant law, but rather is approximately constant.