[@shetrone96b], and the comparison star HD 141531, a giant whose evolutionary status and stellar parameters are comparable to the cluster giants. Though we were restricted to the brightest giants, the globular cluster stars were deliberately selected to span a large range of the star-to-star abundance variations. Table \[tab:param\] contains the list of targets observed using either the Subaru or Magellan telescopes.

Observations of the M 13 giants and the comparison field star HD 141531 were obtained with the Subaru Telescope using the High Dispersion Spectrograph (HDS; @hds) on 2004 June 1. A 0.4  slit was used providing a resolving power of 90,000 per 4 pixel resolution element with wavelength coverage from 4000 Å to 6700 Å. For the Subaru data, one-dimensional wavelength calibrated normalized spectra were produced in the standard way using the IRAF[^2] package of programs.

Observations of the NGC 6752 giants were obtained with the Magellan Telescope using the Magellan Inamori Kyocera Echelle spectrograph (MIKE; @mike) on 2004 April 3-5. A 0.35  slit was used providing a resolving power of 55,000 in the red and 65,000 in the blue per 4 pixel resolution element with wavelength coverage from 3800 Å to 8500 Å. While IRAF was used for 