[1] We welcome the comments by our esteemed colleagues Akasofu and Kamide [2005], but we have to disagree with many of their statements and conclusions. We have strong confidence in the accuracy of the Colaba Observatory magnetic data for the 1–2 September 1859 magnetic storm (the magnetometers worked perfectly before, during, and after the disturbed period of 1–6 September 1859), in the (relative) accuracy of our estimation of a peak DH value of about 1760 nT for the storm (designated in our work as ‘‘Dst’’), and in the extraordinary value/ usefulness of pre-space-age geophysical data. We think that there is much to learn from data such as those from Indian magnetic observatories and other similar data. [2] Tsurutani et al. [2003] used the Kimball [1960] auroral observations and the Wygant et al. [1998] results on electric field penetration in our equation (1) [Tsurutani et al., 2003; see also Volland, 1973; Stern, 1975;Maynard and Chen, 1975; Nishida, 1978] to estimate the magnetospheric convection electric field that was present during the storm’s main phase. From the estimated electric field of 20 mV/m we assumed a reconnection efficiency of 10% to get an interplanetary electric field of 200 mV/m. We next used equation (6) of Tsurutani et al. [2003], the relationship between Dst, Q (the energy input given by Burton et al. [1975]), and t (the ring current decay time). All values were taken at the peak of the storm. The value for t was taken from the Colaba magnetogram. [3] Several consistency checks were made: (1) We performed calculations based on timings provided byCarrington [1859] and empirical relationships developed in the space age to estimate the interplanetary electric field [see Tsurutani et al., 2003, section 4.2]. (2)We noted the Schulz [1997] auroral magnetic latitude versus Dst relationship. (3) We noted the very large negative values of the Colaba DH observations (Colaba is a near-equatorial station (10 magnetic latitude) away from the equatorial electrojet influence and away from severe storm time auroral ionospheric current influence). All of these additional checks gave us confidence in the extraordinarily large Dst value that we derived. However, it should be mentioned that all of the different empirical relationships that were used in our extrapolations were developed for moderate intensity magnetic storms/geomagnetic activity. A data set that could be used to determine whether these relations can be linearly extrapolated to higher values or not does not currently exist. [4] The Colaba magnetometer peak decrease and profile give interesting and new information. The peak DH 1600 nT is the most negative value on record for a near-equatorial station. (It should be noted that Kakioka, Japan (27 magnetic latitude) and Hermanus, South Africa ( 34 magnetic latitude), are located at middle latitudes and are potentially vulnerable to strong magnetic signatures caused by ionospheric currents. They would be useful for studying moderate-intensity magnetic storms but not extreme events such as the one in 1859.) [5] The short duration of the ‘‘main phase’’ of the magnetic storm is indeed quite different from ‘‘typical’’ storms. However, herein lies the usefulness of the magnetic data for new and improved understanding of space weather phenomena. X.-L. Li et al. (Modeling of 1–2 September 1859 super magnetic storm, submitted to Advances in Space Research, 2005) have reproduced the Colaba magnetic profile and Dst peak value by assuming the existence of a high-density plasma plug that followed a magnetic cloud. This is not at all out of the question. Plunkett et al. [2000, and references therein] have noted that coronal mass injections (CMEs) near the Sun typically have three essential parts: bright outer loops, a dark region, and coronal filaments. It is thought that the dark regions are the magnetic clouds that have been detected in interplanetary space. However, the interplanetary signatures of loops and filaments have been more elusive. Tsurutani et al. [1998] have reported the possible detection of a plasma and field signature of loops at 1 AU for the 10–11 January 1997 JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 110, A09227, doi:10.1029/2005JA011121, 2005