AN EXPERIMENT IN BALLOONING.

Auckland Star, Volume XXX, Issue 5, 7 January 1899, Page 5 (Supplement)

AN EXPERIMENT IN BALLOONING.

For some time Mr Percival Spencer, the

celebrated aeronaut, has had it in con-

templation (says the 'St. James' Gazette')

to test the sail trail rope gear used

Andree in his attempt to effect the

aerial conquest of the North Pole. To use a trail rope—without which the sail is practically useless—over land which is cultivated and populated presents some difficulties. No better place could be found than the low-lying marshy country to the north of the Thames estuary; and the wind on the day of trial being- favourable an ascent was determined on. The party comprised beside myself (says the correspondent of the 'Daily Chronicle'), Mr Spencer. Mr Knight (the wellknown war correspondent of the 'Times'), and Lieut. H. O. Mance (of the Royal Engineers), and the ascent was made from the grounds of the Earl's Court Exhibition. The conjoint system of trail rope and soil has never yet been practically tested to any extent, and the idea of it is this. In a. free balloon you are always in a perpetual calm, for you are travelling at the same rate as the wincV A sail would, therefore, be as Httle use for directing purposes as a rudder in a boat drifting in a current without oars or any means of propulsion. To use your sail you must have a trail rope, so that immediately you descend and get a'certain proportion of your trail rope with its weight on the ground your balloon is retarded. You are not then travelling at the same rate as the wind—namely, you are not in a perfect calm, and your sail can aCt. By a proper manipulation of ballast you arrange that a certain portion of your trail rope shall be earthborne, and the course of the balloon correspondingly retarded. You have, however, no guiding power In the trail rope, and for this the sail is used. The retardation of the balloon given by the drag of the trail rope creates a breeze. and this acts on the sail, which by a manipulation of the trail rope causes the balloon to be slanted to the right or left of the wind course, according to the direction in which it is desired to diverge.

At 25 minutes to 2, passing along the line of the Great Eastern to Chelmsford (says the writer), we were at a height of 1700 ft, and throwing out an empty sodawater bottle—we took care to throw It so that it could not possibly do any damage —the thud oh its reaching the ground could bo distinctly heard. At five minutes to 2 we came down and began our trail rope experiments, being then oyer Cranham Hall.' Almost immediately we had got some hundred feet or so of our rope earth-borne we found that it would come straight across a field, and over four ploughs, each with its ploughman and pair of horses. A hail to the men warned them to take their teams forward, our rope trailed safely past the handles of the ploughs just behind them, and a shout from the men gave us our location. One of the prettiest sights of the trip'occurred in a field a little further on. Four young horses were there grazing.and their amazement at the'great weird snake that was swiftly crossing the field was delicious to behold. A wild start and then they trotted up and sniffed ,it deliberately. A shout sent them off in. a headlong gallop, only, however, to trot back again and wonderingly watch the rope, but this time at a discreet distance. At 10 minutes past 2'we had rather an exciting contretemps. We suddenly saw that our trail ropewas bound to pass over the roof of a large house which was hid in thick trees. First resting on the frees at one side, the rope as we crossed dropped straight across the roof. To our delight, however, the chimney pots over which it trailed appeared to suffer no damage, and in a second the rope was again borne on the tree-tops at the other side of the house. This," perhaps, may explain an incident that happened a few minutes later, for, suddenly glancing down, We" saw a burly policeman running for all he was Worth across a field after our trail rope. He never reached it, however, though he made a long run of it, and the last we saw of him he was gazing wrathfully up at us from the centre of a huge ploughed field, evidently too •pumped' to shout. And now a word as to the result of the trail rope experiments.

Our experiments were made at a height of from 300 ft to 400 ft. thus leaving from 100 ft to 200 ft of trail rope on the ground. We found that with this leverage we could work our sail and the balioon to which it was fixed, so that we could diverge a point and a quarter to right or left of the wind.course. In fact, it gave us a range of two and a half points'.wlthin which we could alter the course Of the balloon. With the wind blowing west by south, our course was naturally east by north. COmpass bearings taken showed, it as about half-way between east by north and east. By using the rope reeved through one/pulley and hauling on that end of the sail, the balioon swung at once, and the curve of the trail rope could be distinctly noticed. By-compass bearings we found that we had brought her round to a course E.N.E., namely, about a point and a quarter off the direct course of the wind. Similarly in the other direction we were able by using the other

rope to slew her round to a course of east by south. Mr E. F. Knight is one of the ablest boat sailors in England, and carefully took pur compass bearings for us. We could also tell well by the line of sail, for our wind course lay straight parallel with it, and by the use of our sail we were able to diverge considerably from it. Again, by its use we were enabled to pass to the left of a farmyard and haystacks, over which without its use we would have passed direct. On coming down w-e effected a capital landing in a large field between Billericay and Brentwood, in the parish of Dunton. We landed at half-past 2, the trip having taken us an hour and 40 minutes. The descent was interesting. Your trail or grapnel rope acts as a sort of automatic brake, for it must be remembered that as ydu come down more and more of its weight is earth-borne, and the balloon is correspondingly lightened. It is, indeed, equivalent in a way to throwing out ballast; and so the balloon lowers gently, and does not come down with a rush, although the gas is, of course, pouring from it. ~,,.. ■~. .... , ■ ...