Successful Exploration Through the Interior of Australia by William John Wills
page 37 of 347 (10%)
page 37 of 347 (10%)
|
become unfit for use just when they are most wanted. I think these
evils may be avoided by having the parts of the box which touch any instrument well padded with the most elastic materials, and for it to be supported entirely on steel springs, strong enough to keep it firmly in its place, and with sufficient play to allow the box to warp without injury to any of the contents. I also wish an improvement in the stand of the theodolite, which ought not to be smaller than that of the five-inch one, and the joints made of the metals least likely to sustain damage from friction. The cap-piece should be nearly twice the depth, vertically, and cut out of one solid piece of metal. I subjoin a sketch of it, with the dimensions. It may be made of whatever metal you think proper. There is no harm in having iron about it, because we seldom require to use the needle. My reason for wanting this improvement is, that the legs get loose so quickly from the wearing away of brass, and that the many small surfaces in contact are too disproportionate to their length. Strength and durability are of far more consequence than lightness, as we have not the facilities for getting things repaired here that you have in England. The figures I have placed opposite to the instruments described are not supposed to be the exact prices, but merely suggested as guides. I hope you will do the best you can with the improvements mentioned, especially in the mode of packing the larger articles. Please also to insure them to the full value. I have the honour to be, Gentlemen, Your obedient servant, |
|