Measurements were carried out as opportunity allowed over four consecutive seasons, from the beginning of April until the end of October. During the last of the four years, the site had become less convenient owing to an extension of the railway work, and early in November the series was brought to an abrupt conclusion by a heavy gale, which snapped off all the poles carrying the connecting wire. But by that time 423 measurements had been obtained, the great majority of which referred to clouds of the cirrus and alto groups. The general results may be tabulated thus, giving heights in metres:-- -------------------+-------------+---------+---------+--------- | Number of | Maximum | Minimum | Mean |observations.|altitude.|altitude.|altitude. +-------------+---------+---------+--------- Cirrus | 58 | 27,413 | 4,114 | 10,230 | | | | Cirro-stratus | 64 | 15,503 | 3,840 | 9,540 | | | | „ cumulus | 63 | 11,679 | 3,657 | 8,624 | | | | Alto-cumulus | 83 | 9,390 | 1,828 | 5,348 | | | | Cumulus top | 42 | 4,582 | -- | 3,006 | | | | „ base | 48 | 1,959 | 584 | 1,290 | | | | Strato-cumulus | 27 | 6,926 | 823 | 2,248 | | | | Cumulo-nimbus top | 15 | 6,409 | 2,004 | 8,002 | | | | „ „ base | 15 | 2,286 | 766 | 1,045 -------------------+-------------+---------+---------+---------