Tycho's 1582 Triangular Sextant
Triangular Sextant, about 1.6 meter in radius, built in 1582. As Tycho's sextants grew in size, they became fixed instruments, although Tycho's ingenious globe mount retained a lot of the versatility of use of smaller, conventional portable sextants.
Bibliography:
Thoren, V.E. 1973, Journal for the History of Astronomy,4, 25.
Wesley, W.G. 1978, Journal for the History of Astronomy,9, 42.